The NFL Combine is often referred to derisively as the Underwear Olympics. Coaches, scouts, and other team executives from all the NFL franchises will gather in Indianapolis to watch the best prospective draft picks get measured, take the Wonderlic, and go through various drills and skills evaluations. And a surprising number of viewers will tune into coverage on the NFL Network.
The combine was originated as a way to do these evaluations once and make the results available to all teams, with a level playing field for the prospects. Given that the proceedings are recorded, it seems somewhat old-fashioned to have so many staff go to watch things from the stands.