Visit a restaurant. Ask to look at the mat the guy washing dishes stands on, then ask where to get one.

These mats are appx 1/2 inch tall, perforated rubber. (they come in darn near any size/shape you want...) They are non-slip even when wet and greasy! They hose clean easilly. (they are expensive...) Nice cushion to then to relieve the legs a bit. (but that's not why the restaurants use them... its to keep the dishwasher from slipping and falling.) They seem to last forever. (they also make good entry doormats ... the mud gets tracked in a lot less. )

The actual floor... you want to be concrete or inexpensive vinyl tiles (squares, not sheet vinyl flooring) The tiles are individually replaceable when you destroy one. (and you will occasionally ruin a tile....)

A solid core door on two 2-drawer file cabinets makes a decent workbench (or computer desk. The knob hole is handy for the cords.) Carpenter's shims to level the workbench go under the file cabinets. (screw the door to the cabinets...)

Be sure you Level the workbench... you can check that its straight easier. (and it helps when 'trammeling" and doing incidence checks to be working off of a level surface.)