I'm planning to build a 72x30x2" table top and only own a table saw. After reading some guides, it looks like most people will cross cut the edges to the final dimensions with a track or circular saw. Is this entirely necessary or could the same be accomplished on the table saw with the same accuracy?
I don't think you're going to get the result you want if you make these cuts with a table saw. Cutting large pieces on a table saw comes with a lot of challenges in terms of maintaining the alignment of the work piece with the blade to get a clean, consistent cut. And cutting large pieces always brings the risk of kickback from your saw.
I sometimes sort woodworking cuts into two categories:
- Cuts where you bring the work piece to the tool (e.g., a cut made with a table saw, a hole made with a drill press, etc.)
- Cuts where you bring the tool to the work piece (e.g., a cut made with a circular saw, a hole made with a cordless drill, etc.)
Generally (in my view), the larger the piece, the more it makes sense to bring the tool to the work piece, and the smaller the piece, the more it makes sense to bring the piece to the tool. It basically comes down to which of these is easier (and often safer) to manipulate through the operation. You're looking at making a series of long cuts on a very large work piece.
Although, as Ashlar pointed out, it is possible cut full sheets of plywood on a table saw, the setup needed to do this is much larger than a typical contractor's saw. My table saw can make these cuts, and I still avoid it whenever possible. Plus, a 2" thick glued-up top will weigh an awful lot more than most plywood, which will only add to the handling challenges. Further, the edges of plywood aren't typically a finish surface, so any tearout, burning, or other imperfections generally get hidden by other parts of the finished piece. For your table top, either the cuts will be show surfaces, in which case you want really clean cuts, or they'll be glue surfaces for breadboard ends, in which case... you'll want really clean cuts.
Even if you don't own a track saw or circular saw, maybe see if there's a way for you to borrow or rent one. If it's in your budget, a decent circular saw can be had for not a huge amount of money, and you can fashion up a guide to help you align the cut.
Table saws are often used to cut full sheets of plywood, so your table top can certainly be cut with great accuracy provided you have adequate support for the panel at infeed, outfeed, and side. The outfeed and side are usually supported with mobile tables and rollers and I have seen fold up tables hinge attached to the table saw in lieu of tables on the internet. I provide infeed support using rails similar to the ones shown in the picture (https://jayscustomcreations.com/2014/06/table-saw-infeed-support-arms/). It is very important that the panel have full support for the full duration of the cut so that you need only be concerned with pushing the panel across the blade snug with the fence.