How to keep only Reflections and Shadows but object itself invisible

Question

I want to render only:

1. Object On the white table
2. Table surface reflections
3. Object Shadows on table
4. Emission particles reflections & gloss on table

I want White Table is to disappear totally

It should be kind of Shadow Catcher but with gloss and reflections included. :)

I managed to create attached photo node setup but table now is BLACK color and i can't make it Alpha Channel.

Thanks a lot!