Hi, Jamie! There are non-adhesive PVC products out there that are marketed as shelf liners; a little googling reveals something called "Smooth Top Easy Liner" that might work well for you, and I'm sure there's other stuff like that out there.

I've seen shelves lined with vinyl-faced wallpaper, and that worked out well. Oilcloth could be really pretty; if it's too light to stay put, you could temporarily secure it with some double-sided tape. Or you could even cut cheap plastic placemats to fit.

-- Cam