It makes a huge difference in the type of welding you do. I like a 4 x 10' table because I do a lot of ornamental metal. It has four end to end pieces of angle, clamp hangers, a couple of shelves underneath made of shopping cart material where I can toss my grinder, and hand tools between uses. I have a piece of 4' square plate that cam be put on top when I want a flat surface. A floor mounted table is good if you are welding something really heavy. Having wheels is handy if you have to move things around. So, as mentioned by several contributors, one table does not do it all, and sometimes the good choice is to have more than one if you have the space. A specialty table can get you more work done.