Open Office - Spreadsheet query

[#1]

Just been making a list of "things" on a spreadsheet in Open Office.... have used another spreadsheet prog before, but was ages ago....
this particular one, is just a basic 5 or 6 column sheet, with information in each column with respect to the initial info in the first column.
I need to be able to edit the sheet in the future, by adding a row here and there, - no problem.. and adjusting the columns...  no problem...
what I do need to do is to save it, in it`s current size ,  (so about 6 columns, and 100 rows)  and not the full size "n" number of columns and rows....
can anyone advise me, please,  how to "size" the current sheet to be saved, and possibly printed  ( I know how to do the printing bit ! ! ).on A4 .(portrait style, as it is inclined to be presented that way)...

[#2]

You don't really remove the millions of empty rows / columns from a spreadsheet.
I think the closest thing you can do is hide the gridlines and then format the used cells to have borders.

[#3]

I presume you are trying to minimise the size of the file.
Don't worry/bother. Spreadsheet programmes don't actually store the cell contents as a grid. They use some form of linked list (Excel calls them streams) and only cells that contain data or individual formatting are stored.

[#4]

ok.Thanks guys... I have just "saved" it, and it has not saved the millions of spare cells.... which was my reason for the query... !....
the file size did not enter my head  ! 
I have since re-opened the file and it works fine..... thanks guys