I have data tables that need to be put in my thesis and they have to be in landscape mode since there are more columns and the headings have to be the same in all the sheets. The compilation takes too long on overleaf. I am also using the package threeparttable as I want to use table notes to make one comment at the end of the table. The MWE used is given below. I want to know if the method I have used is correct. or is there a better way to do it?
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\begin{documnet}
\begin{landscape}
\begin{table}[ht]
\footnotesize
\centering
\caption{Continuum and emission-line flux variability characteristics of Mrk 335 of the period 1978 to 1993.}
\label{335}
\setlength\tabcolsep{0pt}
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\begin{tabular*}{\linewidth}{@{\extracolsep{\fill}} cc cc cc cc cc cc c }
\toprule
Obs. Dates
& \makecell{ $\lambda_{o}$ \\ (\AA) \space}& Spectrum ID.
& \makecell{ F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (min)} & snr & Spectrum ID.
& \makecell{ F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (max)} & snr
& \makecell{ F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (avg)}
& \makecell{ R$_{max}$ $\pm\ \Delta$R$_{max}$ }
& \makecell{ F$_{var}$ $\pm\ \Delta$F$_{var}$ }
& \makecell{$\Delta$T \\ (days)}
& N \\
\midrule
%% table body
18-01-1979 / 04-02-1984 & 1350 & SWP22205 & 6.85 $\pm$ 0.14 & 5.87 & SWP03938 & 14.59 $\pm$ 0.04 & 11.91 & 7.31 $\pm$ 0.04 & 2.13 $\pm$ 0.04 & 15.19 $\pm$ 0.07 & 1843 & 35 \\
18-06-1990 / 19-01-1990 & 1450 & SWP39107 & 7.3 $\pm$ 0.03 & 14.3 & SWP38051 & 13.47 $\pm$ 0.13 & 10.38 & 6.76 $\pm$ 0.03 & 1.85 $\pm$ 0.02 & 15 $\pm$ 0.13 & 149 & 27 \\
18-01-1979 / 10-08-1990 & 1605 & SWP39439 & 7.5 $\pm$ 0.03 & 12.5 & SWP03938 & 13.44 $\pm$ 0.04 & 8.36 & 6.35 $\pm$ 0.03 & 1.79 $\pm$ 0.01 & 15.16 $\pm$ 0.09 & 4222 & 36 \\
18-01-1979 / 04-02-1984 & 1675 & SWP22205 & 5.82 $\pm$ 0.02 & 7.12 & SWP03938 & 11.91 $\pm$ 0.03 & 19.18 & 5.84 $\pm$ 0.03 & 2.05 $\pm$ 0.01 & 16.22 $\pm$ 0.06 & 1843 & 38 \\
18-01-1979 / 04-02-1984 & 1812 & SWP22205 & 4.78 $\pm$ 0.02 & 9.05 & SWP03938 & 10.31 $\pm$ 0.01 & 9.32 & 5.46 $\pm$ 0.03 & 2.16 $\pm$ 0.01 & 15.87 $\pm$ 0.07 & 1843 & 39 \\
31-12-1983 / 04-02-1984 & 2475 & LWP2532 & 6.01 $\pm$ 0.04 & 5.55 & LWR17238 & 3.83 $\pm$ 0.02 & 8.4 & 4.3 $\pm$ 0.03 & 1.95 $\pm$ 0.02 & 14.47 $\pm$ 0.08 & 35 & 29 \\
31-12-1983 / 04-02-1984 & 2625 & LWP2532 & 4.93 $\pm$ 0.02 & 8.27 & LWR17238 & 3.09 $\pm$ 0.01 & 6.37 & 4.1 $\pm$ 0.03 & 2.1 $\pm$ 0.01 & 13.72 $\pm$ 0.06 & 35 & 36 \\
31-12-1983 / 04-02-1984 & 2875 & LWP2532 & 4.27 $\pm$ 0.02 & 13.18 & LWR17238 & 2.98 $\pm$ 0.02 & 9.9 & 3.63 $\pm$ 0.02 & 3.19 $\pm$ 0.03 & 37 $\pm$ 0.07 & 35 & 37 \\ \hline
\end{tabular*}
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\begin{tabular*}{\linewidth}{@{\extracolsep{\fill}} cc cc cc cc cc cc c }
\toprule
Obs. Dates & \makecell{Emission \\ line} & Spectrum ID.
& \makecell{ F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (min)} & Spectrum No.
& \makecell{ F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (max)}
& \makecell{ F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (avg)} & EW (\AA \space)
& \makecell{ R$_{max}$ $\pm\ \Delta$ R$_{max}$ }
& \makecell{ F$_{var}$ $\pm\ \Delta$ F$_{var}$ }
& \makecell{$\Delta$T \\ (days)}
& N \\
\midrule
%% table body
05/07/1978 - 19/07/1990 & Ly$\alpha$ & SWP39252 & 99.78 $\pm$ 1.05 & SWP01919 & 29.57 $\pm$ 0.01 & 64.675 $\pm$ 1.03 & 195.83 & 2.96 $\pm$ 0.03 & 31.86 $\pm$ 0.1 & 4396 & 37 \\
05/07/1978 - 22/01/1985 & Si IV & SWP39439 & 10.47 $\pm$ 0.7 & SWP24944 & 31.18 $\pm$ 0.92 & 20.83 $\pm$ 0.81 & 24.44 & 2.98 $\pm$ 0.22 & 25.95 $\pm$ 0.86 & 2026 & 30 \\
22/01/1985 - 30/06/1991 & C IV & SWP41962 & 49.44 $\pm$ 0.76 & SWP23250 & 108.1 $\pm$ 0.45 & 78.77 $\pm$ 0.61 & 151.37 & 2.19 $\pm$ 0.03 & 17.95 $\pm$ 0.17 & 2350 & 42 \\
30/07/1983 - 31/12/1983 & He II & SWP20544 & 11.5 $\pm$ 0.57 & SWP21922 & 44.86 $\pm$ 0.67 & 28.18 $\pm$ 0.62 & 43.775 & 3.9 $\pm$ 0.2 & 35.71 $\pm$ 0.5 & 153 & 35 \\
22/01/1985 - 18/06/1990 & C III] & SWP39107 & 5.92 $\pm$ 0.79 & LWP05247 & 75.8 $\pm$ 0.42 & 40.86 $\pm$ 0.61 & 95.002 & 12.8 $\pm$ 1.71 & 82.96 $\pm$ 0.68 & 1973 & 40 \\
04/09/1981 - 30/07/1983 & Mg II & LWR11470 & 6.78 $\pm$ 0.52 & LWR16482 & 27.91 $\pm$ 0.31 & 17.35 $\pm$ 0.42 & 51.035 & 4.12 $\pm$ 0.32 & 44.29 $\pm$ 0.62 & 694 & 23 \\
\bottomrule
\end{tabular*}
\end{table}
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\begin{longtable}{@{\extracolsep{\fill}} cc cc cc cc c}
\caption{Annualized continuum and emission-line flux variability characteristics of Mrk 335. }
\label{annual_335}
\toprule
\makecell{ $\lambda_{o}$ \\} (\AA \space) / Line
& \makecell{F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (min)} %Spectrum ID. &
& \makecell{F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (max)}
& \makecell{F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (avg)}
& EW (\AA \space)
& \makecell{R$_{max}$ $\pm\ \Delta$R$_{max}$ }
& \makecell{F$_{var}$ $\pm\ \Delta$F$_{var}$ }
& \makecell{$\Delta$T \\ (days)}
& N \\
\midrule
\endfirsthead
\toprule
\makecell{ $\lambda_{o}$ } (\AA \space) / Line
& \makecell{F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (min)} %Spectrum ID. &
& \makecell{F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (max)}
& \makecell{F$_\lambda$ $\pm\ \Delta$F$_\lambda$ \\ (avg)}
& EW (\AA \space)
& \makecell{R$_{max}$ $\pm\ \Delta$R$_{max}$ }
& \makecell{F$_{var}$ $\pm\ \Delta$F$_{var}$ }
& \makecell{$\Delta$T \\ (days)}
& N \\
\midrule
\endhead
\midrule
\multicolumn{9}{r}{\small\textit{Continued on the next page}}
\endfoot
\bottomrule
\endlastfoot
& & & & \textbf{1981} & & & \\
2625 & 4.59 $\pm$ 0.02 & 5.19 $\pm$ 0.02 & 4.89 $\pm$ 0.02 & - & 1.33 $\pm$ 0.01 & 12.68 $\pm$ 0.24 & 267 & 4 \\
2687 & 4.43 $\pm$ 0.04 & 4.88 $\pm$ 0.04 & 4.66 $\pm$ 0.04 & - & 1.45 $\pm$ 0.02 & 16.25 $\pm$ 0.55 & 267 & 4 \\
2875 & 4.19 $\pm$ 0.02 & 4.6 $\pm$ 0.02 & 4.4 $\pm$ 0.02 & - & 1.37 $\pm$ 0.01 & 13.65 $\pm$ 0.24 & 267 & 4 \\ \hline
Si IV & 1.99 $\pm$ 0.1 & 1.53 $\pm$ 0.08 & 1.76 $\pm$ 0.09 & 19.24 & 1.3 $\pm$ 0.09 & 14.21 $\pm$ 3.04 & 267 & 3 \\
C IV & 6.13 $\pm$ 0.1 & 6.41 $\pm$ 0.06 & 6.27 $\pm$ 0.08 & 73.39 & 1.05 $\pm$ 0.02 & 2.34 $\pm$ 0.85 & 267 & 3 \\
C III] & 1.85 $\pm$ 0.07 & 6.38 $\pm$ 0.06 & 4.12 $\pm$ 0.07 & 40.66 & 0.52 $\pm$ 0.19 & 70.91 $\pm$ 1.1 & 0.26 & 6 \\
Mg II & 0.98 $\pm$ 0.05 & 0.79 $\pm$ 0.05 & 0.89 $\pm$ 0.05 & 16.42 & 1.45 $\pm$ 0.12 & 19.02 $\pm$ 3.57 & 63 & 3 \\ \hline\hline
& & & & \textbf{1982} & & & \\
1350 & 10.57 $\pm$ 0.03 & 10.58 $\pm$ 0.04 & 10.58 $\pm$ 0.04 & - & 1.06 $\pm$ 0.01 & 3.49 $\pm$ 0.21 & 0.26 & 3 \\
1450 & 9.32 $\pm$ 0.06 & 8.93 $\pm$ 0.07 & 9.13 $\pm$ 0.07 & - & 1.16 $\pm$ 0.01 & 7.41 $\pm$ 0.43 & 0.26 & 3 \\
1605 & 10.46 $\pm$ 0.06 & 9.98 $\pm$ 0.06 & 10.22 $\pm$ 0.06 & - & 1.18 $\pm$ 0.01 & 8.29 $\pm$ 0.32 & 0.26 & 3 \\
1675 & 9.26 $\pm$ 0.03 & 8.31 $\pm$ 0.04 & 8.79 $\pm$ 0.04 & - & 0.9 $\pm$ 0.01 & 10.97 $\pm$ 0.26 & 0.26 & 3 \\
1812 & 7.71 $\pm$ 0.03 & 7.2 $\pm$ 0.02 & 7.46 $\pm$ 0.03 & - & 1.13 $\pm$ 0.01 & 6.16 $\pm$ 0.23 & 0.26 & 3 \\
Si IV & 2.38 $\pm$ 0.09 & 1.97 $\pm$ 0.08 & 2.18 $\pm$ 0.09 & 24.88 & 1.21 $\pm$ 0.07 & 9.72 $\pm$ 2.32 & 0.14 & 3 \\
C IV & 6.73 $\pm$ 0.08 & 6.37 $\pm$ 0.07 & 6.55 $\pm$ 0.08 & 87.18 & 1.16 $\pm$ 0.02 & 7.79 $\pm$ 0.66 & 0.14 & 3 \\
He II & 2.39 $\pm$ 0.07 & 2.65 $\pm$ 0.08 & 2.52 $\pm$ 0.08 & 37.91 & 1.34 $\pm$ 0.06 & 15.11 $\pm$ 1.54 & 0.14 & 3 \\
C III] & 3.29 $\pm$ 0.06 & 1.08 $\pm$ 0.07 & 2.19 $\pm$ 0.07 & 25.5 & 3.14 $\pm$ 0.22 & 60.26 $\pm$ 2.12 & 0.07 & 4 \\ \hline\hline
& $\pm$ & $\pm$ & & \textbf{1985} & & $\pm$ & & \\
C III] & 2.3 $\pm$ 0.05 & 7.58 $\pm$ 0.04 & 4.94 $\pm$ 0.05 & 81.88 & 4.78 $\pm$ 0.11 & 85.59 $\pm$ 0.95 & 174 & 3 \\
C IV & 7 $\pm$ 0.06 & 10.81 $\pm$ 0.05 & 8.91 $\pm$ 0.06 & 153.07 & 1.54 $\pm$ 0.01 & 23.7 $\pm$ 0.41 & 174 & 3 \\ \hline \hline
& & & & \textbf{1989} & & & \\
1350 & 12.03 $\pm$ 0.03 & 9.24 $\pm$ 0.02 & 10.64 $\pm$ 0.03 & - & 1.49 $\pm$ 0.01 & 15.27 $\pm$ 0.11 & 182 & 10 \\
1450 & 10.91 $\pm$ 0.06 & 9.5 $\pm$ 0.05 & 10.21 $\pm$ 0.06 & - & 1.39 $\pm$ 0.01 & 11.16 $\pm$ 0.22 & 182 & 7 \\
1605 & 12.29 $\pm$ 0.05 & 9 $\pm$ 0.04 & 10.65 $\pm$ 0.05 & - & 1.53 $\pm$ 0.01 & 13.27 $\pm$ 0.14 & 182 & 10 \\
1675 & 10.15 $\pm$ 0.04 & 8.33 $\pm$ 0.03 & 9.24 $\pm$ 0.04 & - & 0.82 $\pm$ 0 & 12.89 $\pm$ 0.12 & 182 & 11 \\
1812 & 9.87 $\pm$ 0.05 & 7.44 $\pm$ 0.03 & 8.66 $\pm$ 0.04 & - & 1.63 $\pm$ 0.01 & 14.18 $\pm$ 0.13 & 182 & 11 \\
2475 & 6.51 $\pm$ 0.02 & 5.38 $\pm$ 0.01 & 5.95 $\pm$ 0.02 & - & 1.31 $\pm$ 0.01 & 11.32 $\pm$ 0.14 & 182 & 6 \\
2625 & 5.72 $\pm$ 0.02 & 4.88 $\pm$ 0.01 & 5.3 $\pm$ 0.02 & - & 1.24 $\pm$ 0.01 & 8.91 $\pm$ 0.12 & 182 & 6 \\
2875 & 5.04 $\pm$ 0.01 & 4.18 $\pm$ 0.01 & 4.61 $\pm$ 0.01 & - & 1.29 $\pm$ 0 & 11.12 $\pm$ 0.25 & 182 & 6 \\ \hline
Ly$\alpha$ & 14.37 $\pm$ 0.04 & 13.2 $\pm$ 0.1 & 13.79 $\pm$ 0.07 & 176.69 & 1.43 $\pm$ 0.01 & 11.4 $\pm$ 0.22 & 182 & 9 \\
Si IV & 1.82 $\pm$ 0.08 & 3.08 $\pm$ 0.07 & 2.45 $\pm$ 0.08 & 24.36 & 2.12 $\pm$ 0.1 & 26.58 $\pm$ 1.63 & 29 & 7 \\
C IV & 6.32 $\pm$ 0.06 & 6.26 $\pm$ 0.09 & 6.29 $\pm$ 0.08 & 93.79 & 1.33 $\pm$ 0.02 & 9.79 $\pm$ 0.38 & 58 & 9 \\
He II & 3.16 $\pm$ 0.08 & 4.1 $\pm$ 0.05 & 3.63 $\pm$ 0.07 & 42.14 & 2.24 $\pm$ 0.06 & 28.59 $\pm$ 0.95 & 29 & 7 \\
C III] & 3.96 $\pm$ 0.06 & 1.19 $\pm$ 0.09 & 2.58 $\pm$ 0.08 & 19.66 & 5.49 $\pm$ 0.43 & 71.22 $\pm$ 1.87 & 54 & 9 \\
Mg II & 2.55 $\pm$ 0.04 & 1.2 $\pm$ 0.04 & 1.88 $\pm$ 0.04 & 31.24 & 3.03 $\pm$ 0.11 & 42.57 $\pm$ 1.25 & 54 & 7 \\ \hline\hline
\end{longtable}
\begin{threeparttable}
\begin{tablenotes}
\textbf{Note:}\\
Dates of Observation correspond to the continuum flux minima and flux maxima.
Continuum and emission-line fluxes - minima, maxima and average are in units of 10$^{-14}$ erg/s/cm$^2$/\AA \space and 10$^{-13}$ erg/s/cm$^2$/\AA \space respectively.
N is the number of epochs of observations considered for computing mean continuum and emission-line fluxes and its error. F$_{Var}$ is in percentage.
\end{tablenotes}
\end{threeparttable}
\end{landscape}
\end{document}
