Usage patterns
〈人〉が昼食をとるfor someone to have lunch
She has lunch at the company cafeteria every day.
昼食を済ませるto finish eating lunch
I finished lunch before the meeting.
昼食に〈物〉を食べるto eat something for lunch
I ate a sandwich for lunch.
昼食の時間lunchtime; the lunch break
Lunchtime is from noon to one o'clock.