What purpose does Launcelot serve in the play at this point?

Lancelot, Shylock's servant, is referred to as the "clown". He perceives Shylock as vicious and "devil"-ish, but he finds himself unable to leave Shylock due to a sense of duty. When Lancelot's father offers a gift to Shylock, however, Lancelot tells him to offer it to Bassanio instead, as Bassanio is the man Lancelot would rather serve.