I wouldn't see why not. They may need to be deleted one by one via the in-game library. [Select one, and click the trashcan in the lower left hand corner of the popup.]
However, if you want to delete a whole bunch of files at once. Exit the game, and go to your Tray folder, highlight all the files and click delete. - Click one file and then press the A and Ctrl keys together to select all then hit delete.
Path -- \Documents\Electronic Arts\The Sims 4\Tray
This is assuming you've backed up the houses/lots and household files you want to keep backed up.
MrsFlynn