@KiLa
Just a quick report back, there is more to getting the wavetable properly formatted than the naming convention.
First, there is the naming. This is puzzling, since this applies to User wavetables, but does not apply to UVI or third-party wavetables. Perhaps those are making use of metadata to cover the same ground.
In short, if your sample is 24 bit and 48kHz, then you need a suffix for the file name and this one seems to work: name_2048
I've lost track of how to fix that number, and I'll be doing additional research to try to pin down the rules.
Second, the audio of the file itself must be appropriately arranged. I have not yet found out precisely how. In theory, it seems that you should be able to do this with just the editing facilities in a DAW. However, for now, I'll be using software into which you can import any audio sample and it will then reformat that sample for you.
Pigments does this automatically; Falcon does not. Vital (which is free) will allow you to input any audio sample (or image, I think - which Falcon can do too) and it will format it for you, allow you to edit it, and then export it as a wave file.
Basically, drag and drop your wav file (others probably work too) into an oscillator, and open the editing (click on the little pencil icon). Go up to the save options in the editor, and you can choose to export as a wav file.
So, after around nine months, this is far as I've managed to get. Now, I can take a sample of a bassoon, use Vital to convert it into a wavetable wav file, which I name, say bassoon_2048 and then I have my new wavetable. If you own the original sample (or it is CC0), then you now own the created wavetable.
I have a lot more work to do to learn what I presume are basic facts that I would have expected to be posted all over the place. Perhaps the problem is the amount of 'information' out there, and the inability of search engines to distinguish between reliable and detailed information and chatter.
If anyone can recommend a book or course to learn about these things that are suitable for a very technically inept imbecile to understand, please do let me know.