How much peanut butter do you have to put if 2 tablespoons of jelly?

This depends on personal preference, so there is no set answer. A common ratio of peanut butter to jelly is 1:1, so if you are using 2 tablespoons of jelly, you would also use 2 tablespoons of peanut butter. However, some people prefer more peanut butter or more jelly, so you may want to adjust the ratio according to your taste.