Oh no! Just when you thought you'd solved the problem.
When we eat somewhere besides the table, we use
these trays from Ikea. Lightweight, little grips at the handles and raised edges all around. I usually put a placemat on top, but it's mainly to catch spills and drips. Would that prevent slippage with your Corelle?
If you need cheap, easy to replace crockery, we like Ikea's
Dinera range in grey-blue. They're stoneware, sturdy and have a nice weight to them. They're not fancy, but they do the trick for us.
We've got our usual set of Denby crockery (amazing, but not cheap) but we're living at FIL's house right now and... ahem... no one washes dishes properly.
As in they use their hands (which they don't usually wash) and fingers to 'wash' plates... no soap.
So, yeah. We got our own set of crockery to use for the year we're here.
The Ikea Dinera set has been perfect for us (and a steal at £23 for six settings) and we'll probably take it with us when we leave because we like it so much.
Could you keep the Corelle for table dining and buy something else for eating on the couch? It's so pretty it'd be a shame to be rid of it, although I'm sure it would be very welcome to someone else here.