Actually, your description seems fairly clear. But I don't have a clue what it's for. My guess is, it has nothing to do with cooking.

When you described holes of various sizes, the first image that came to mind was a drill-bit gauge. It's used for identifying drill bits by size (since many drill bits are too small to have readable markings). I suppose a gauge like this wouldn't need to have circular holes; semicircular holes along the edge of the plate might work.

A drill-bit gauge wouldn't need a handle, though.