Serum has a Wavetable editor built right in- you can create your own wavetables in a variety of ways.
IMPORT YOUR OWN AUDIO / CREATE CUSTOM WAVETABLES WITH EASE The dream synthesizer did not seem to exist: a wavetable synthesizer with a truly high-quality sound, visual and creative workflow-oriented interface to make creating and altering sounds fun instead of tedious, and the ability to “go deep” when desired – to create / import / edit / morph wavetables, and manipulate these on playback in real-time.