I'm tall (5'11" ) and I have some issues with my back and I found that cutting on the kitchen table, my sewing table (a Horn) were too low. My husband made me a portable cutting table extension with removeable legs. This is what he did:
He got a piece of wood from the hardware store that is the same size as my 24x36 cutting mat. It is actually a little bit smaller but I can cut on the whole thing. There is a tiny bit of overhang. Then he got some ready made table legs and attached them. I put felt pads on the bottom so that they don't scratch up the kitchen table. The legs screw into a metal piece. For my comfort and ease of moving it around he attached metal handles to the sides.
When I want to use it I pull it out from under the guest bed, screw in the legs and set it on top of the kitchen table or wherever I am cutting. It is the perfect height for me. Then when I'm done I just take the legs off and put it away.