AutoFill can be a timesaver if you often work with common lists of data. You can define your own custom lists and then use them over and over again, as described here.

A great timesaver when entering data is to use Excel’s AutoFill feature. To use the feature, enter enough cells that Excel can figure out how you want to fill the remaining cells in series. For instance, enter 1 and 2 into two cells, or 5 and 10 into two others, or Monday and Tuesday. Select the two cells and then click and drag the Fill handle at the bottom-right corner of the selection border.
As cool as AutoFill is, an even cooler timesaving feature is to define your own series of values that AutoFill can use. Follow these steps:

1. Click the Office button and then click Excel Options. Excel displays the Excel Options dialog box.
   Make sure Popular is selected at the left of the dialog box.
2. Click Edit Custom Lists. Excel displays the Custom Lists dialog box and hides the Excel Options dialog box.
3. Select NEW LIST in the Custom Lists list.
4. In the List Entries portion of the dialog box, start typing the items in your fill series, in the order they should appear. For instance, you might type a list of department managers in alphabetic order. Press Enter at the end of each element.
5. When you are done, click the Add button.
6. Click OK to close the Custom Lists dialog box. The Excel Options dialog box reappears.
7. Click OK to close the Excel Options dialog box.

You can now use the custom list for the AutoFill feature. Simply type whatever entry from the custom list you want to start with, select the cell, and then drag the Fill handle. Excel fills the selected cells with the items from your custom list, in order.