Like all other MS Office programs, Excel offers many convenient keyboard shortcuts to help make dealing with spreadsheets easier. Most people know about using the arrow keys, Enter, and Tab to navigate cells, but here are some other useful key combinations to make Excel more convenient:

Action Shortcut
Insert a new line within a cell [Alt] [Enter]
Enable editing within a cell [F2]
Add a comment to a cell [Shift] [F2]
Open Print Preview Ctrl [F2]
Fill selected cells with an entry you typed in one cell Ctrl [Enter]
Fill data down or to the right through selected cells Ctrl D or Ctrl R
Create a name Ctrl [F3]
Insert the current date or time Ctrl and ; or Ctrl and :
Create a chart from a range of data [F11]