I second a wood top of some sort. A stainless table top is going to make noise every time you set something down.
I've used those jointed pine "project boards" from Home Despot for table and cabinet tops. They are soft wood but the top surface holds up pretty well when finished with polyurethane. Put a hardwood edge around the perimeter to protect the edges and corners.
For extra weight, laminate the pine project board to an underlay of MDF. You won't see the MDF if you edge the thing with hardwood.
A totally ready-to-go-without-any-woodworking solution might be a table top or counter top from Ikea. Their AS-IS clearance area can have some decent deals.
Of course, if you go the Ikea route for a reloading bench top, you'll only be able to load 6.5×55 Swedish on it -- nothing else will work properly with an Ikea top.
I have the ikea butcher block top and I can confirm that non Swedish calibers can be loaded.



















































