You tagged excel so here is a solution in excel:
You need to click on that column with the merged cells and unmerge all cells.
Then you need to put this formula at the top of your list and enter it with ctrl+shift+enter(this will enter it as an array formula):
=OFFSET(C3,MAX(IF(NOT(ISBLANK(C$3:C3)),ROW(C$3:C3),0))-ROW(C3),0)
Then you need to autofill that down.(this function seems a little verbose but I just got it online - there is probably a simpler way to do this - but it finds the last nonblank cell in a range).

I think openoffice has similar functions so you should be able do the same or something similar in openoffice.
Alternatively if you are using excel you could click on the column you want to unmerge and run this macro:
Sub UnMergeSelectedColumn()
Dim C As Range, CC As Range
Dim MA As Range, RepeatVal As Variant
For Each C In Range(ActiveCell, Cells(Rows.Count, ActiveCell.Column).End(xlUp))
If C.MergeCells = True Then
Set MA = C.MergeArea
If RepeatVal = "" Then RepeatVal = C.Value
MA.MergeCells = False
For Each CC In MA
CC.Value = RepeatVal
Next
End If
RepeatVal = ""
Next
End Sub
Good Luck.
EDIT:
I found a Non-VBA solution that will work in both excel and openoffice and doesn't require you to enter it as an array formula(with ctrl+shift+enter):
=INDEX(B:B,ROUND(SUMPRODUCT(MAX((B$1:B1<>"")*(ROW(B$1:B1)))),0),1)
In open office I think you want to enter it like this:
=INDEX(B:B;ROUND(SUMPRODUCT(MAX((B$1:B2<>"")*(ROW(B$1:B2)))),0),1)
or maybe like this:
=INDEX(B:B;ROUND(SUMPRODUCT(MAX((B$1:B2<>"")*(ROW(B$1:B2)))),0))
You just need to autofill that formula down:
