What happens to this after the event? The venue surely has its own supply of tables so they will not be keeping these and your next party is not likely to be another Alice in Wonderland theme. They're hard to store, so straight to the landfill?

This appears to be made of expanded polystyrene (EPS), the same substance that forward thinking cities are trying to reduce the use of to lessen pollution.

Creatively neat, environmentally bad.

Or trapped in the mountains due to a snow storm, forced to do unspeakable things to survive the winter.