Will walks in the kitchen and, finding Geoffrey playing blues on a harmonica, makes a joke about walking in on "Blind Lemon Pledge". He's making a pun on blues singer/guitarist Blind Lemon Jefferson.
Will warns Carlton that baldness is hereditary. To which Carlton freaks out and runs out of the room. While it's true that baldness is hereditary, it is not inherited from your father. It is inherited from your maternal grandfather. So unless Vivian's father was bald, Carlton has nothing to worry about.