Does anyone know the purpose or back-story of St Clair glass "mini plates" like this one?

[ltldpr]

They wouldn't make good coasters.

I suppose you could use one for putting a spoon you're cooking with on so you don't mess up the counter or stove top. 

They're not as attractive as other art glass, so I thought they might have a function or purpose, but can't seem to find what it might be. 

Edit: thought not though

[pickapaper]

I don't think these mini plates have an actual purpose or story other than being decorative.  Looks like they were made in various colors and designs, mainly to depict coins.  Would look cute to put several in a group on a table top. 

[rockystradingpost]

They may have been samples to show the colors.

[krazzykats]

Cup plate.

Cup plate - Wikipedia