This is an overview of the built-in tables, their use-cases and their waveform visualisations.
Historically, often entire wavetables were dedicated to emulating other types of synthesis or specific instruments. Because the wealth of other synthesis algorithms on the Woovebox already cover these, these eight built-in wavetables were carefully selected to play to wavetable synthesis' unique strengths, rather than covering the same ground already covered by the other algorithms.
That said, you can of course import any custom wavetables in the unlikely event the built-in ones are insufficient for your needs. All tables originate from the CC0 1.0 wavedit-online GitHub repository, where you will find many more wavetables of varying quality and usefulness.