Here is another robot that can greet and serve customers at restaurants. This humanoid robot waiter is based on Android. It has an ARM Cortex-A8 processor with 512MB RAM and Android on-board. It has WiFi and Bluetooth connectivity. It comes with smart obstacle avoidance and various facial expressions.
This robot has adjustable speed (0.6-0.8m/s). Its tray can hold up to 10kg of load. You can find out more about it here.