[Tman1]

Sounds like a good place to use Baltic birch plywood. I would not use mdf for this application. It is good in compression for providing a flat stable surface, as long as it is in a dry environment (you get it wet and it will swell and never return.) It will also expand and contract some with changes in humidity. I'm sure there are other materials that would work well too. But mdf is not one of them.

 

[Tman1]

Just to clarify on the expansion and contraction of mdf comment. It isn't as bad as wood, but it does happen. One of the reasons I know this is because I have an mdf router table top. There is enough humidity fluctuation in my shop that I have had to make small tweaks to the height of my router plate in the router table to keep sharp edges from getting caught going onto or off of the plate. I also had a piece that was warped and I could flip the warp from side to side by laying one side on concrete.

For a router table top, it should work fine, as long as you don't cover the top and leave the bottom exposed. Then, it will most likely warp. I would not recommend it for cabinet body or any structural application that will put bending or tension stresses on it. It will break apart fairly easily in those conditions, which is why it doesn't hold screws well.