Please help me understand this sentence...

가끔 친구하고 저녁을 먹고 산책을 할 때도 많이 있어요.

"Sometimes I have dinner with a friend and ..."

I don't understand the second part. "When strolling a lot"? What is 많이 doing?

I know all the words in this sentence but I don't get it.

I need to make an anki card out of this. Your help is appreciated.