The bed in "The Tell-Tale Heart" symbolizes the opposite of what beds and bedrooms should be about. The narrator violates all bedroom etiquette, by exploiting the vulnerability of one who is sleeping. We are perhaps most vulnerable in bed, and we sleep well when we feel safe in our bedrooms. Poe turns the symbol of the bed on its head. The narrator uses the bed as weapon to snuff out the old man. And since the bed is the murder weapon, it's logical that the bedroom is the burial place. Creepy.