Add row above and insert data

For this I would use the Categories feature. It should take just a few minutes. Do something like this:

On the left is your table with the original data. Make sure you have a backup of it just in case.

1. Click in the column in the table that has RV02, RV03, etc., and in the menu go to Organize > Add Category for "C" [or whatever header you used for that column]. The result should be similar to the middle table in my screenshot.
2. Create a new table on that sheet.
3. Select the body cells in the categorized table (the middle table in the example) and command-c to copy.
4. Click once in cell A2 of the newly created table from step 2 and Edit > Paste and Match Style.
5. In Row 2 of an empty column on the right (I used Column F) enter a formula like this: =IF(NOT(ISBLANK(A2)),A2,E2). Fill that formula down the column.

In that column you should now see the data in the format you want. You can copy-paste the data wherever you need it by typing command-c followed by Edit > Paste Formula Results.

SG

When you click the red warning triangle, what error message does it show?

Have you by any chance set your computer to a region that uses , as the decimal separator, i..e instead of 100.50 as in the US you would instead write 100,50? If so, use semicolons in the formula instead of commas, e.g.

=IF(NOT(ISBLANK(A2));A2;E2)

BTW, I don't think it makes a difference but it appears that in Step 4 you used command-v or Edit > Paste instead of Edit > Paste and Match Style. That would explain why you have all those shaded cells that I don't have in my example.

EDIT. I think you can IGNORE THE ABOVE. Your column setup is different from what I had in the example. You are referring to the same cell E2 that the formula is in. Instead try:

=IF(NOT(ISBLANK(A2)),A2,D2)

SG

Glad it worked on your end.

SG