Can silk oak mulch be used in vegetable garden?

I believe that any type of mulch may be used. Wooden mulch is for the most part decorative, but it also deters weed growth. I would say there aren't any disadvantages to Silk Oak mulch unless you know it to be particularly basic or acidic, in which case you would have to compensate.

I would advise using a compost as a topsoil before applying the mulch.