Adding multiple rows/columns to a spreadsheet in Calc

From NeoWiki

Inserting more than one row/column at a time

• To insert multiple rows into a Calc spreadsheet at one time, select the same number of rows as you want to add, beginning at the row AFTER where you want the insertion to be, then ctrl-click/right-click on the row header (where the row numbers are) within your selection, and choose Insert Rows from the contextual menu - or click on the Insert Rows button in your toolbar if it's visible there.

• To insert multiple columns, just follow the above instructions subtituting 'columns' for 'rows' - it works exactly the same way.