One of my cats scratches next to her food when she does not care for what I gave her and when she has finished eating. She usually does it until I pick up the food and move it. I usually say to her "well, you don't have to eat it if you don't want it!" Maybe she is trying to "save it" for later, but I think it is her expression of wanting it gone since she does it with food I know she does not like.
