A table saw is for lengthwise cuts, for cutting long things like these you need a cut-off saw.

Fun fact, you don’t really need to tap soft aluminium like this. You can just drive the bolt straight in with an impact driver. I thought it was sketch at first, having always tapped them beforehand. But my buddy said it’s a waste of time, just drive the bolts in right away. So I tried it and he was right, it works perfectly every time. They form perfect threads so you can easily remove and re-add the bolt just like when it was tapped beforehand.