An ashtray...

The plate is captioned "Playing Roulette Las Vegas, Nevada". It doesn't look like a Nevada scene to me.

The cool thing about the plate is the sticker on the back, which says:
"Royal Nevada GIFT SHOP
ROYAL NEVADA HOTEL * LAS VEGAS, NEVADA"

...and it's a Royal Winton plate, made in Staffordshire, England, which probably explains why it doesn't look like Vegas!