This is kind of a loaded question because there is no one-size-fits-all welding table. It’s going to depend on a lot of different factors, like what kind of budget you have, how much space you have, and how big the projects are that you want to tackle. But arguably, the size of the table is less important than the type of table. The most important thing about a welding table is how flat it is, followed by how usable is it.
In order to achieve flatness, you really need a three-dimensional table that has a rib infrastructure to support the surface. That way, no matter how much weight you put on it, it’s not going to sag underneath the weight.
Now, one of the other benefits of these types of 3D tables is that since they have side walls that are very perpendicular to the surface, you can actually bolt together multiple smaller tables in order to create one large surface. So this will actually allow you to initially invest in a smaller, higher-quality table and then later, if you find you need more surface area, you could buy an additional table and use them together.
In addition to bolting tables together, you can purchase table extensions that can be added temporarily or permanently, and you can even use things like Fab Squares to bolt to the side to temporarily support larger materials.
My general advice is to buy the largest table you can fit in your space if at all possible. If your space is limited (or your budget), it’s Ok – that’s what extensions and other bolt-ons are for. You can treat your table as modular and grow or shrink it as needed.