Why the western restaurant to serve from the right, what are the advantages and disadvantages

Because the service staff to give you food, the left hand to take the tray or dish is, the right hand to put down more convenient. On the other hand, this is a respect for the guests, but also to facilitate the guests, because the guests are right-handed chopsticks, or tea and so on, so from the right side of the food is more convenient. Imagine, if the food waiter from the left on, it is inevitable that will run into the guests, and put food although thoughtful waiter personal, but the guests also have to move a little more