Why did Dickens include chapters 31-33

You are correct,there isn't too much to add from these chapters. I think Dickens loved the theatre and wanted to add this into his narrative. Dickens presents a light hearted critique of overacted theater in this chapter. Wopsle's Hamlet is laugh-out-loud comedy. Dickens was an actor and a producer of theatrical productions himself, and there is no doubt he was probably targeting certain actors that he knew personally in this parody.