Lovely montage of leaves made to fit the large Trofast tray 
Sit it at one end of the tray, leaving space to fill your tray with rice, chick peas and other sensory messy play items, and scoop them up into your tray sections 
 
You get a 3mm solid base, and hollow 6mm top layers, which you simply need to glue to the base to create the trays
Any white craft glue works well, here's a link to ours 

Learning Aids, Resources, MDF Craft (perryswoodcraft.com)