Sanding & Oiling walnut slab table

I’m making a table out of two thick walnut slabs.
My question is in regard to the order of sanding and oiling.
I’m working on the underside now and put a coat of Tung oil on, thinking it’s good to put this down before attaching the legs.
When doing the top of the table, do I oil, sand repeatedly working my up to a fine course, then oil again? How many coats before/after sanding? I believe I want about 5 or so coats of tung oil.
I’m sure it’s obvious that this is my first technical (to me) wood project.

Thanks a bunch,
Jay