Ableton's Wavetable synth ships with over 100 wavetables built in, but this bit shows how to bring your own sounds into the mix. Drag any sample, like an arp lead pulled from the User Library, straight into the Oscillator's Visualization section and Wavetable converts it into a playable wavetable on the spot.
Once loaded, movement through the shape can be driven by an LFO modulating wavetable position, giving the sound that evolving, alive quality instead of a static tone. This is a fast way to turn found sounds, recordings, or synth patches into raw material for new textures.
Browsing sibling files in the same folder is just as quick. Open the dropdown chooser to see every compatible file in that directory, or skip the mouse entirely and use the up and down arrow keys to cycle through neighboring wavetables while auditioning them in context.