Most of the time I clean them up, push them all together, and throw some toys on the trays in hopes they stay at least a few minutes before all landing on the ground (seriously, the other day I taped bead necklaces to the trays & attached all toys to the beads... and they still managed to get all the toys on the ground in 10 minutes!).
The other day I was bored with the regular toys, and then I realized--- hey! I have lots of "toys" for them that are free and easily accessible--- in the kitchen! Oh, what fun they had!
Who knew cookwear could be so much fun?!?