mid century vintage ceramic dishes w/ horses, Kentucky Derby souvenirs lot

Lot of five small dishes with different horses, all mid century vintage (made in Japan, though only some of them are marked).

These are 4" and 4 1/2" in diameter - trinket dishes, or nut bowls? Maybe ashtrays? They were souvenirs of Derby day, many years ago. All are in good clean condition, no chips or cracks.