Grab Bite Lunch Eat I Time Quick B

"When do you want to go grab a bite?"
"I don't have much time, so let's grab a quick bite."
"If you didn't have lunch yet, let's grab a bite to eat."

A: "Did you have lunch yet?"
B: "Not yet. I'm swamped with work."
A: "You have to eventually eat so let's just grab a bite somewhere close."

Other Common Sentences

"Let's go eat."
"Where should we have lunch today?"
"Let's have lunch together."