My shop is too small to manage cutting down full sheets of plywood or other sheet goods on the table saw without a major cleanup and re-arrangement each time, so I break them down to manageable size outside my shop using one of my circular saws and a straight edge. I have developed a system for this that is as accurate as my Unisaw.
I made a cutting table that is 30" wide and 6' long, using the metal folding leg assemblies that are available from Harbor Freight for about $25. The table itself is an open frame with cross pieces only where necessary to hold the legs, plus one cross piece in the center. All of the outside pieces of the frame are 2x4 standing on edge. The cross pieces are all 2x4 stock laid flat and flush with the top of the frame. I used biscuits and glue to assemble it all so there would be no metal anywhere near the top surface. The only metal that is in the wood are the short screws that attach the leg assemblies.
When it is set up I can lay a full sheet of plywood or other sheet goods on it and use a straight edge and my circular saw to cut the sheet down to manageable sizes for finish cutting on my table saw. I set the depth of the circular saw so that it cuts through the sheet stock plus about 1/8" to 1/4" into the top of the table and I don't worry about the saw kerf table damage. If I ever make enough cuts into it to make it unusable I can easily make another frame and transfer the legs to it. A big advantage of this table is that you can make your cuts without the cutoffs falling to the ground or breaking off at the end of the saw cut when they fall, as frequently happens when using saw horses. It stays right there on the table top until you pick it up to move it. The holes in the top keep you from piling junk on it too. I have even used this table for some router work and it has proven very useful for that too. When it isn't being used, it folds up and stores easily with my sheet goods. The legs fit up inside the 2x4 frame when they are folded, making it only 3 1/2" thick. In a pinch, a sheet of plywood thrown on top of it makes a good extra picnic table or assembly table too.
For rapid positioning of the straight edge, make yourself some scrap blocks of wood that are the exact width of the distance between your circular saw's blade and the edge of the saw's base. Make one to fit the long side of the saw and another one for the short side of the saw. They eliminate the offset measurements for your straightedge. You just place the one that you need between your straightedge and your cut line and then clamp the straightedge in place. It makes this setup very quick, and allows very accurate and repeatable cuts, but be sure to mark them with something visibly obvious so you don't cut them up to use for a future project.
To minimize circular saw chip-out on the top surface of your saw cuts , make yourself a zero clearance plate for the bottom of your saw that is the exact same with of your saw's base. Mine is made of 1/8" clear lexan, but it could be thin plywood, attached to the foot of my circular saw with a countersunk flathead bolt up through the lexan and the saw's base at the front of the saw and another one at the back, with wing nuts on the top side. Once attached the first time, plunge the saw blade slowly down through the base until it is fully down. Turn off the saw and then mark the base for cutting it out to clear for the saw guard. Don't use it without doing this. Only mark for the cut far enough forward to allow the guard to drop fully, leaving the front area with only the blade width cut. This area where the blade teeth rise up through this base performs the zero clearance blade function and must be left intact. Now remove the base and make the cutout to clear the saw guard where you hd marked with a sabre saw, coping saw, etc. It doesn't have to be an accurate cut, just large enough so that it doesn't interfere with the blade guard. Replace the base on the bottom of your saw and check to make sure that the saw blade guard functions properly. Also make sure that the outer edges of the attached base are even with, and parallel to, the edges of the saw base, as any difference here will cause the saw to be offset from the straightedge and not cut accurately. You are now ready to make chip-out free saw cuts.
Charley