With the Auto Fill feature, you can automatically fill cells with data that follow a pattern or series.
Select a cell and type the first word of a series (e.g. type "January" for a 12-month series).
Select the fill handle at the lower-right corner of the cell, hold down, and drag to fill the rest of the series. Fill handles can be dragged up, down, or across a spreadsheet.
Note: If you only enter a three-letter abbreviation (e.g. "Jan") in the cell, Auto Fill will automatically fill in the rest of the series.