When you’re two years old and have not yet had the pathways in your brain hardened into what generally appears to be a rut, everything can do everything. Anything is possible. In this case, a tray table is a coloring bench/food holder. After, it becomes a tunnel and cave in which one might drive a bus.
I watched Claire set herself a place with coloring books and food and appropriate a chair. Then I watched her tuck herself into a corner and pull the tray table over her so she could drive her bus underneath it. Then she played hide and go seek. Tray tables are, apparently, base.
Tool users! Humans are pretty clever when they open their brain up. Yes they are.