The full name of PDR is Private Dining Room, which means private restaurant in Chinese. Pdr of catering department refers to private dining places set up in traditional business places such as restaurants and bars.
Application example of PDR:
A few days later, we ate in a restaurant, which was very lively. There were many people waiting in line for the table, but strangely, we were led through the queue and entered a private restaurant.
For example, Coach and Horse Bar in West End of London opened the "Su He's Secret Tea Room" in its private restaurant last year to attract more customers when customers were scarce.
Degang Guo, wearing sunglasses, swaggered into the club at night, followed by a group of well-dressed men, who were taken to an elegant private room in the back.