"What do you like to do when you're not in the office?"

This is another question where they want to find out some of your hobbies. Basically, you can answer this question similar to how you would answer, what are your hobbies.

"When I'm not in the office, I like to play golf, read magazines, and spend time with my wife."

"Well, I like the piano so I have piano lessons on a weekly basis. I also like gardening, so I work on my yard a lot. But if I want to relax, I like to watch videos at night."

Something short and simple is the best answer. No need to elaborate on why.