Material information: Stainless Steel Sheet, 0.8mm thickness, EN 1.4016, sanded (K240), magnetic
I bought the stainless steel from a metal shop in Germany:
http://designbleche.de/
However I am sure, you can get similar material in many places. I had the stainless steel sheet cut to order.
You are correct, most stainless steel sorts are not magnetic - as I am using magnets for fixing feeders, holders etc. I specifically wanted a magnetic material.
I used a polyurethane glue to laminate the sheet to a MDF plate.
I chose the sanded surface to reduce reflections which might interfere with camera.
So far I am happy with the performance. Steel is much sturdier than other table tops. It is easy to clean, ESD safe and when I crash the machine into the table, the nozzles will certainly break before you scratch the table
Most important: I can fix my board holders, strip feeders, individual part trays etc. using small magnets and move them around as needed.
Camera is no problem. Obviously, you cannot detect individual parts on the metal surface - but for detecting parts in feeders, fiducials on PCB and so on the extra reflection has not caused issues for me.
Please be warned that cutting or drilling stainless steel requires special tools. Also, if I planned my table again, I would probably not go for a large table surface again but rather cover only 2/3 of the work surface to make room for feeders, drop areas, camera etc. in sort of a "open frame" construction.
Hope this helps.