I think 5'x10 is a common very large work area size, but usually a table top is glued together from smaller pieces right? I don't think you will need a table this large, I mean you won't be cutting a table top from a larger blank of wood. I don't think you can even get wood that large, if you could, think of how expensive it would be. If you were planning on spending 30k, look at used industrial machines. you can get huge ones for that price, but that is out of the diy scope, and you would need a very large space, and high power requirements. If you were talking about engraving the top of a large table, you can get a very wide or large machine, but I would have a 4x8, manageable size machine, for doing 90% of the work, and a smaller one to sit on top of the table and engrave whatever designs I wanted.