I just finished this table and had to share it with fellow woodworkers. The main table is 78" long. There are two 18" extensions, so 9.5 feet total. I designed the base and extension hardware/brackets and had a local metal shop I work with fabricate everything. Each extension has four set screw/knobs that screw into the brackets to make everything flush and prevent pulling out.
My finishing steps for the top were BLO -> dewaxed shellac -> five coats of gloss wipe-on poly -> two coats of semi-gloss wipe-on poly.