There was a thread last year that dealt with some things concerning (MBSID) wavetables, where I tried to give a simple example of a wavetable function (see message #5 in the thread). It’s not thorough by any means, but maybe it will get you started, and you can ask more specific questions later when you (hopefully) have a rudimentary idea of how the wavetables work. (See also the manual’s section ‘WaveTable Configuration menu’.)