New Expansion: Wave Table.

[updater295]

I Need New Expansion: Wave Table Synth Module.

[N-SPC700]

If you open module properties window, you can select the N163 or FDS options. Those are wavetable synthesis chips.

If you want anything else, such as a new wavetable synthesis chip of some kind, this isn't the tracker for you, as this tracker only supports chips officially added during the Famicom's lifespan. Additionally, this specific fork of FamiTracker is most likely dead in terms of development, as the last commit is 5 years old by now, so if I were you, I wouldn't expect anything new from this specific fork, as it currently stands.