A tray assembly is provided for use with a carrier in a product sortation system. The tray assembly includes a platform to receive parcels loaded onto the carrier. A pair of movable edge members are disposed at opposite sides of the platform. Each edge member is integrated with a combination including a pair of pivotable support arms and a spring element intermediate of the support arms. Each support arm supports its edge member at one end and is pivotally mounted at another end to a tray framework. The spring element is fixedly mounted at one end to the tray framework and is connected at another end to its edge member in a biasing relationship. In response to an applied load resulting from a parcel bearing down on the edge member, the support arms pivot downward in a manner sufficient to allow the parcel to reach and then rest on the tray platform. At the same time as the support arms pivot, the spring element deflects. After the package is unloaded from the tray platform, the return action of the spring restores the edge members back to their original location, as guided by the support arms.