A tray formed from a blank of sheet material includes a bottom panel, a top panel, first and second side panels, and a locking band connected to the bottom panel at opposite upper and lower edges thereof. The locking band extends across the top panel and holds an underlying portion of the top panel in face-contacting relationship with the bottom panel. The tray is configured to transition from a first, substantially flat configuration into a second, erect configuration in which the top panel defines a concave surface configured to hold in place a rounded item. The tray is configured to be transitioned from the first configuration to the second configuration by sliding the top panel relative to the bottom panel.