A ladder accessory assembly that can be attached to a ladder. The assembly includes a platform that can be attached to the ladder by a fastener assembly. The platform is of a size that can create or extend the effective shelf space of the ladder. The platform may have mounting features that allow tool accessories such as paint cans, paint trays, etc. to be mounted to a working surface of the platform. The tool accessories are mounted in a way that inhibits tipping of the accessories.