If you are talking about what I think you are. You can either tile your tables or cascade them. Tiling them would allow you to see all of your tables completely(up to a max amount of course) at the same time. Cascading them would organized them diagonally down your screen from left to right.
How you can do this just depends on the poker client you are playing on. Many of them have an option in the menu or with some button located on the client to do it for you. Which poker site
are you looking to do this with?