When approaching any design I try to simplify things down to the most basic form I can that meets the requirements of the project.
The lowrider really doesn’t even need a true table only 2 parallel rails with enough cross supports to keep the spoil board from sagging. It’s basically a bed frame with slats.
The lowrider 2 had some weird requirements because of the wraparound z-axis that forced my table to look like this:
But if I was building a LR3 I think I’d just use a pair of I-Joists from HD for rails. They come in 22 foot lengths and are engineered to resist deflection .