When open and slipped onto the tray (with a tie to make it stay put) - there is a pocket on the right meant for a cup, a pocket on the left that holds a felt puzzle/matching game (numbers on one side, animals on the other side) and a center pocket with three panels (one we use for crayons, one for stickers and another for snacks).
On the top panel there is a white board with pen. On the other half is card stock paper.
There is also a pocket on the bottom panel to put books in. And, it all folds up nicely to slid into a bag or backpack.
Here's to lots of happy use during long plane rides :).