Hi,

You can insert multiple rows or columns into an excel worksheet by selecting the desired quantity in advance.

To select multiple rows:
1. Click the row indicator at the left edge of the worksheet, then drag down to select the desired quantity of rows.

2. Right click over the selected area, then choose Insert from the context sensitive menu that appears.
The number of rows you selected is inserted above the selected rows.

This works for colums too, as well as in tables in Word.  See a demonstration here: