at/in the club

[sitifan]

The word “sandwich” first appeared in the 18th century. John Montagu, the fourth Earl of Sandwich in England, often gambled at London’s Beef Steak Club. Sometimes he stayed at the gaming table for twenty-four hours. He didn’t want to stop gambling even when he was hungry, so the cooks at the club put some beef between two pieces of bread for him. This way, the earl could eat without leaving his seat. This new kind of food became very fashionable, and the people in the club named it a “sandwich” after the earl. Then in 1837, an American writer wrote a recipe for ham sandwiches in her cookbook. Sandwiches became very popular after that. (Kangxuan Book 5, p2)
What's the difference in meaning between "at the club" and "in the club"?

 

[jutfrank]

I think the people in the club is supposed to refer to the members whereas the cooks at the club refers to non-member staff.