What is this?

I bought this little thing at the flea market years ago because it was blue and white and cute but I have no idea what it is. My guess would be a butter or cheese dish but it's very small so I'm not sure. I put it by a coffee mug so you can get an idea of the size. The inside is shaped like a shallow bowl. I know someone out there will know what it is!Feel free to take a guess even if you're not