I was gifted a set of 3.5 inch floppy disk silicone floppy disk coasters. They didn't come with a holder.  

I came across techdumpling's gridfinity 3.5-inch floppy disk holder, which was perfect for a start. I remixed it to have more slots and with the logo of the coaster set. 

Just uploading this here in case anyone else receives this set and needs a holder for them.