The gifts that are left by Boo Radley for Jem and Scout in the knothole of the Radley oak are meant to be a message of friendship from the most mysterious man in Maycomb. Boo has been watching the children play in front of his house, and the gifts serve as an ice-breaker between them. Some of the gifts have specific significance; some do not. The chewing gum found by Scout, with its shiny outer foil wrapping glittering in the sunlight, is the first gift. It seems to have no significance other than being an irresistible treat for Scout--and which Jem determines is not poisonous. (Remember, the Radley pecans are believed to be deadly.) The Indian-head pennies are probably just some coins Boo had laying around the house, but to Jem they are "strong magic... good luck." The carved soap images are meant to be likenesses of Jem and Scout, and the "tarnished medal" was probably the spelling bee medal won by Boo himself when he was a child. As for the watch, chain and knife, Boo may well have seen Jem playing with his grandfather's watch, which Atticus let him carry once a week; now he would have one of his own. And the knife seems to be author Harper Lee's way of foreshadowing the knife that Boo uses to save the children at the end of the story.
At the beginning of the novel, Boo Radley is described as the "malevolent phantom" who is depicted as a monstrous beast that terrorizes Maycomb. Initially, the children believe the false rumors about their reclusive neighbor. As the novel progresses, Scout and Jem begin to find gifts in the knothole of the Radley tree. The gifts are essentially Boo's way of communicating with the children. Since Boo is extremely shy and rarely leaves his home, he attempts to develop a relationship with the children by giving them gifts. His gift-giving is significant because it portrays his magnanimous personality, which contradicts the negative rumors about him. The reader can determine from Boo's extension of friendship that he is a kindhearted, selfless individual. Some of the gifts seem to hold more significance than others. The carved figurines must have taken a substantial amount of time to make, which suggests that Boo truly cares about Jem and Scout. Also, the Indian-head coins, spelling bee medal, and watch may have meant a lot to Boo. Giving Jem and Scout gifts that possibly hold personal significance depicts Boo's strong feelings of friendship toward the children.