This is a candy puller, the candy he's pulling into small strips is similar to nougat and made from sugar, egg white and sometimes honey. He says he makes a big slab of it the night before, filled the middle with roasted peanuts,and wrapped it in plastic, so it will not dry out and become brittle.
Then all day he unwraps it, pulls out little strips of peanut filled nougat and his wife carefully puts them into little bags for sale. It's 20 baht for a bag of about 10 pieces.
I always find it interesting to see things done the old fashioned way.
Catch him at at the place shown on the map below, not far from Ratchawong Express Boat Pier in China town. You can also see the nougat photographed close up on my food blog.