I like the foam floor. I have a few of those foam tiles, but what I used for the floor around the reloading area are those thick rubber horse stall mats from the feed store. If I drop a die or my calipers, it's better than the hard concrete. I even put one on the top of the desk. So that's my suggestion.
My reloading desk has a top. I'm not sure if it's melamine or formica. It's fake wood grain on top of sheet steel.
This isn't my desk, but it's just like it. It's a Steelcase Tanker desk. I put the horse stall mat on top. It works great. Nothing slides and even cases don't roll far.
I don't have my press mounted on it. My presses are on floor stands, not a bench. I never liked the idea of trying to build a benchtop to withstand the torque of a press. I mount them on a heavy steel column bolted to the floor and a steel tripod stand.
I don't use the rubber top for cleaning. I clean my handguns in a polymer cart:
The brass tumblers are in the bottom.
The reason I mention this is because I doubt the rubber mats are as chemical resistant as formica or melamine. I use the solvents in that cart.