Agree with all PPs. Get there exactly at opening to ensure a table. Shop a bit, have appetizers, etc. otherwise, you will likely not get a table. We go every sunday of our trip (sometimes lucky enough to have 3 ) and always get a table at opening. Then see people wait for hours and never get a table. The food is absolutely fantastic too BTW! The rueben is to die for on the Boardwalk Bakery's homemade rye bread.
for a 1 PM game, we start lining up at about 11:15 AM, but we have a certain section/table we like to sit in on the bar side. You should be ok getting there up until noonish.
PS - great bloody marys there so you're not sitting there staring at the wall for 1.5 hrs before the game starts!
The ESPN Club will pretty much be packed all day long. For the 1:00 game, a line will already be formed by opening at 11:30. Anything goes for the 4:00 game. There could be die hards who will stay for the entire day. There will be people who leave after the first game - but remember that the games usually overlap!
Basically, no matter when you go on a football Sunday, you are going to have a line.