Yeah I use Serum for all wavetable stuff. It has a nice size, 2048 samples pr wave as standard.
Just be aware that Serum uses what they call morphed wavetables, which is often 256 waves wavetables. But in reaility they only consist of maybe 8 waves whcih are morphed between to get the 256 waves.
From what I have experienced if you try to export these morphed wavetables, you only export the 8 waves, NOT the full 256 waves.
But to be honest I have not tried to export them the same way as @lokki is talking about here. @lokki does Serum actually also export the morphed waves when doin it like you suggest here or only the few actual waves that is morphed between?