Go User_Manual#Apartments, see Apartment/examples.
New (2022): this feature allows you to manage many objects by creating themed configurations (for example an Atysmas configuration, Anlor Winn configuration, a Friends Reception configuration, etc.). You can have several decoration configurations, and switch from one configuration to another in one click.
Source: https://app.ryzom.com/app_forum/index.php?page=topic/view/32228/1