"I've hung out in the writer's room a few times, but the fact is we've got such a good writing staff, I don't want to get my peanut butter fingerprints on anything"

Patton Oswalt is describing the imaginative procedure of composing for tv. He has actually remained in the writer's room a few times, however he knows that the writing personnel is really skilled and he doesn't wish to interfere with their work. He is recommending that he doesn't wish to obstruct of the creative procedure by leaving his "peanut butter fingerprints" on anything. This is a metaphor for leaving his own personal mark on the work of the composing personnel. He is recommending that he is content to observe and not interfere with the creative process. This quote is a testimony to Oswalt's regard for the composing staff and their work. He is aware that he is not as knowledgeable as the composing staff and he doesn't wish to obstruct of their innovative process.