A board for rolling dice inside so they can remain contained. Glue foam or felt into the tray for it to make it quiet. We normally play on a wood table and the dice go everywhere in games like Tenzi or Dragonwood. 

This helped contain the dice but not make the game so loud when playing. 

I tried gluing both foam and felt. The foam is VERY quiet but kinda sticky for fast games. The felt works better for all around.  You can just leave it off to contain the dice but the noise level is a little higher. The curved edges help to get the dice off quicker. 

Recommend using some rubber gripper stickers on the bottom. 

Pictures are of a prototype.