This role is not described in the manual. Jokes should be in good taste, the kind you would be comfortable telling in a business setting. Here is a place where you can learn to tell a joke, well. The following is one site that has some good, clean fun in some 40 categories: http://jokes.christiansunite.com/
There are other sites on the internet and in book collections. You can personalize a joke by putting yourself in as a character. Or it can be in third person. The point is to start off the meeting with some lightness.