The formula below will extract the SUM of the range you specify. Of course, there are other things you might do with the range.
=SUM(OFFSET($B4,0,0,MATCH(FALSE,ISBLANK($A$4:$A$4000),0)-1))
Key to this function is the assumption that the "Content End" row in column A is the first non-blank cell in column A after the first cell of the range ($B$4 in the above formula). The "Content Start" cell is immaterial but it might be used for defining the first cell of the range if that is required.
If the intervening rows aren't blank you can adjust the MATCH function to look for "Total Cash out" instead of False.
The range $A$4:$A$4000 is arbitrary but the first cell must be on the same row as the start cell of the range. I recommend a named range in place of the address.
Note that the MATCH formula was advertised as an array formula but it works as normal on Excel 365. If you have a problem with the formula try entering it with Ctl+Shift+Enter