I need a round table, 78-84" in diameter, that I can build around a permanent pole that supports a roof. The center of the table must have an 18-24" hole to fit around the pole. The table should be collapsable and moveable.

Wood veneers are shaved off a log as it spins, so can be quite wide, although they break eventually. The substrate could be 4' x 8' plywood/particle board/MDO.
I don't think you'll find a round table made out of a 7' diameter tree! And it makes no sense, because of course it has to be made in sections - you want it to be movable!
Two sections are the minimum and sound best to me.
Because of the size and the sections, I would make it out of solid wood (glued lengths). Glued sections are stronger than large single pieces anyway, and help prevent warping.
So if each half is about 40" wide, and each board used is 10" wide, you'll have 4 boards glued together, twice.
And that way there is very little waste, because the outer edges of the 2 halves can be very short pieces, gradually getting longer towards the middle ones.