The cafeteria operation manged by Flik Internation, a unit of Compass Group, that serves players and staff of the Cleveland Browns NFL team in Berea, OH, largely resembles a college dining hall. At least that's the impression given by this video tour of the facility with commentary from Flik chef Chris Brunst.
While the NFL is in its offseason currently, players do come in for scheduled offseason workouts and "voluntary" Offseason Training Activities (OTAs). Meanwhile, coaches and stadff are at the facility regularly, meaning that the cafeteria must function daily for all three meal periods.
The offerings as described by Brunst in this video range from standard menu items like burgers, chicken and salads to treats like sweets. There's no mention of how much typical NFL behemoths might eat in a sitting but nutrition has become critical to all high end sports operations and all meal choices come with intricate nutritional information.