Why are not all wavetable editable?

Why are not all wavetables editable, some are greyed out.


do you mean some of the modifier/source are greyed out?

If they aren’t editable, its probably samples, (.wav instead of .vitaltable), or an “audio file source”.
There are 3 sorts of source possible in the wavetable editor, only wave and line are editable, but on the audio file you can add modifiers.