What is the best worksurface for polymer? I will be doing most of my cutting and rolling in my living room -  so I need a portable setup. Sanding and dirty work I would do in my basement.

I have a couple of marble slabs available, and some kitchen counter cutofs and some glass that I used to use for cutting on.

The counter top would be the most convenient for portabilty, it wont break and weighs the least and I can cut it to the size I want  - but I'm not sure how it holds up to repeated blade cutting

The marble is the  worst, its heavy

The glass from previous experience is good for cutting- but the highest risk of breakage, and I will have to pay for the piece I have (which broke) to be cut down to size and edge finished.

 I use glass primarily, sometimes with parchment paper if I'm making thin bits I don't want to distort peeling off the glass (parchement paper can go right in the oven).  Your bigger problem is probably the pasta machine, if you are using one...  it's nice to be able to clamp it down.

When I teach my polymer clay fundamentals "boot camp" workshop, I provide every student with a 12 x 12 inch smooth, ceramic tile. I get them very inexpensively at my local big box discount home improvement center. I then give each student a square of that stuff you can get to put under area rugs to keep them from slipping --  it does the same thing under the tile!  Happy claying, Jill ;)

I just picked up a Sculpey pasta machine - I was planning in using one that I had in storage, but its rusted and not usable. I have a high shelf in a cupboard where I can keep it- but would not be able to put the glass or marble slab up there.  can clamp it on my dining room table, which over the last few years has served as a painting easel, a sign manufacturing line, and a stained glass workbench. (I have stopped using the living room as a workarea for sheets of plywood since my family found that excessive LOL)

The ceramic tile idea is intersting, I have a supplier 5 minutes down the street that I get clearance tile form for mosaic