Here's the problem. You want to display some models on a diorama base somewhere or set up a game on a table. Easy enough except it has to be packed away after and maybe carted around.
It would also be nice if the groundwork was easy to remodel depending on what you want.
The ideal thing is a sand table. The problem is that a sand table has to be very strong as a thick enough sand base is going to be extremely heavy - hard to pack up and cart as well.
Since most people end up using a dining table or similar, sand is just not the answer. I've tried it and it's also too messy.
After much experimentation which is still ongoing I have decided on the following;
A sand table that is a sand table in every way except I don't use sand.