Manager:	고생 많으셨어요. 피곤하시죠, 형님. You’ve worked hard. You must be tired, Jung-hui.
Jung-hui:	응, 완전 피곤해. 그거 말고 커피 줘. 커피 없어? Yeah, I’m really tired. Give me coffee instead of that. Is there any coffee?

고생 많으셨어요 (You’ve worked hard)

고생 – (n.) trouble, hardship
The state of one’s going through sufferings or hardships or such a life.
많다 – (adj.) plentiful; many; a lot of
A number, amount, etc., exceeding a certain standard.

Casual – 고생 많았어.
Semi-polite – 고생 많았어요.
Polite – 고생 많으셨어요.

>>[고생 많았어요] is similar to the expression [수고 많았어요] which means “you’ve done a great job.”

>>In the dialogue, the expression is used as a polite gesture to express sympathy for Jung-hui who has worked hard at his job. Contextually, the expression would mean “You’ve worked hard today. You deserve a break.”

>>The expression is also commonly used as a polite verbal gesture to express thanks to someone who may have been helpful to you. In most situations, it's the equivalent of saying "You've been to an unusual amount of trouble (so thank you)."