As Like many others I saw the wyrmwood kickstarter and felt like making my own version of their organizer trays.
All pieces print without supports, and you'll need 1 base, 3 legs and a top for each tray.
Then you'll also need a cork coaster and 12 10x2 magnets... Or whatever you want to put in a 10mm x 3.4mm slot. Everything just then snaps together.
Make sure that the top legs holes are not aligned with the legs as the polarity of the magnets will prevent them from stacking otherwise. (my rendered pic is wrong)
AMAZON APPARENTLY SHIPS RANDOM SIZED COASTERS FROM THIS LINK SO IF YOU'RE UNLUCKY THEY'LL BE 4" DIAMETER
Coasters (90mm diameter, 3.2mm thick) for bottom: https://www.amazon.com/gp/product/B075TGD8XM
10x2 Magnets: https://www.amazon.com/gp/product/B0753ZPBLQ
(these are actually 1.7mm thick and each slot takes 2, so you could also use 3mm thick ones)
2019-04-18 Added a RA triple tile as the original has an unintentionally steep side.
2019-04-29 Added caster and dice jail tiles. The caster tile uses 4mm ball bearings, and it's wand uses one of the 10mm magnets (which may be far too big, but who wants to buy yet another size XD) untested as I am waiting for ball bearings from china apparently. Also there is a model of the cork insert if you want to try using infill as a coaster.
2019-04-30 Added a raised text version of the caster tile. Also added pdf printable templates for the cork size and the inside of the rolling tile if you want to line it with felt or something (print without scaling.)