bethsinc_xx The Tray folder contains your saved households and builds, so if you deleted that folder, the data is gone. Sims 4 doesn't sync files automatically, so you'd only have the local copies. And a factory reset of your laptop would just permanently delete everything, not bring your data back.
If OneDrive is running on your computer, whether you ever deliberately use it or not, you could check onedrive.com for your missing Tray files. Look in both My Files and the Recycle Bin. Tray files have extensions like .bpi, .blueprint, trayitem, .hhi, or .sgi, and each in-game item has several corresponding files, so make sure to grab everything.
The Slot_ file is a save, not a Tray item.