Re: Tray folder

@tissueboxes  The Tray folder is in Documents > Electronic Arts > The Sims 4, and this is the folder that contains your saved households and builds.  So you can download someone else's household or build and add it to your game by simply placing the provided files inside Tray.  The files need to be directly in Tray, not in a subfolder, and they need to be unzipped.

The Tray folder is only for saved library items, not mods or custom content.