This is a table that I built from the remains of an EZ-Up canopy that had gotten mangled by a tornado. It opens to about 24x24" and stands 36". I cut the corner posts down to get it to a comfortable working height for me. It can even be adjusted up another 8".
It's a multipurpose table, but so far the only top that I've made was this welding top, which is the bottom tray from an old window air conditioner. I ugly-welded pieces of scrap L channel to the underside to keep the top from sliding around. It's not fixed to the base at all.
Here's a close-up of the textured appearance finish that I put on the top.
I just rocked a grinder with a 120g flat wheel randomly around the surface to get that machined-surface look.