do you mean you want 'blocks' of data repeating across the page, and then down, such as a 5 X 5 grid
Via the dataassist wizard, I don't think there is an option to do this, however, you can achieve it by creating a DataAssist Repeating Table
This may give you what you want
Insert-->Webassist-->DataAssist-->RepeatingTable
In the repeating table wizard, you get to specify the number rows and coulmns you want in your layout