This function takes an existing design and steps it out as many times as requested. The file will always get bigger because you are increasing the number of actual repeats by the amount specified. 

1. Use the keyboard shortcut ⌘ D to ensure there are no selections in the file.
2. Go to the Edit Menu and select Step & Repeat. The following window will open and will display the document size at the top. 
   
   
3. Enter the number of repeats and the drop amount and click OK. The file will step out accordingly and the size of the file will increase.
   
   

If you set a drop such as a ¼, ⅓ or ½ drop in the Step and Repeat Window, a space will be visible at the top of the document where the second row of repeats has been dropped:

Use the Crop Tool to cut out the repeat:

Once the correct repeat size has been cropped, use the Repeat Window to put the new document size into repeat.