Tom’s Tutorials For Excel: Repeating Your Last Action FAST! The Magic of the F4 Key.
Take a look at this gem: The F4 key is a little-used but highly efficient shortcut for speeding up your Excel tasks, when you need to repeat the same action once, twice, or dozens of times.
In Excel (and other Office apps as well), many tasks can be instantly completed by hitting the F4 key for as many times as you want to repeat your last action. The following pictures (formatting ranges, inserting new worksheets, and deleting rows) are just three examples that are repeatable with F4.
First example — Formatting ranges
Second example — Inserting worksheets
Third example — Deleting rows