Flash Fill automatically fills your data when it senses a pattern. For example, you can use Flash Fill to Combine first and last names from two different columns and to fill a column of Company e-mail addresses.
Make sure your Flash Fill is turned on. You can go to Data > Flash Fill to run it manually, or press Ctrl+E. To turn Flash Fill on, go to Tools > Options > Advanced > Editing Options > check the Automatically Flash Fill box.