Your description is confusing because you mention "downloading" from a disc. You can copy files from a disc or install from a disc but you "download" from the Internet. Also what do you mean by a "small" disk. I'm not aware of any PC games distributed on mini CDhttps://en.wikipedia.org/wiki/Mini_CD
Is there a particular eBay auction you're looking at?
There was a version of the first Book of Unwritten Tales game from around 2009 that was a physical release. I don't know about Book of Unwritten Tales 2. Mobygames only mentions a German physical release of Book 2.http://www.mobygames.com/game/book-of-unwritten-tales-2/cover-art
The trouble with a lot of current "physical" releases is that they're little more than a Steam code in a box and the game either needs Steam activation or an entire download from Steam. Beware of pictures on eBay that are just "representations" and not the actual thing being sold.