I recently salvaged some short lengths from a large Grey Gum tree that was approximately 70-90 years old.
After getting my chainsaw serviced, I cut these short lengths into "slices".
A number (about 30) of these slices were from a branch high up in the tree and are about 250-300mm across. Most are 25-60mm thick, have the edges rounded and will have a few coats of polyurethane applied. Apparently these have been used as centre pieces on tables at weddings etc.
A smaller number (less than 10) are cut from higher up the main trunk and are about 450-550mm across. I plan to make these into small side tables. We have one in the corner of a bathroom to put odds and ends on.