In my research I found this on Replacements for $279.00 and they call it a mayonnaise bowl. The bowl is attached to its base plate.

It is in good condition with some crazing on bottom and some wear to edges.

See photos.

Markings are 1920.

Vibrant colors of navy, yellow, pink pop on the white  porcelian with black shading.

dish 6.5 x 6.5 in

bowl 6 x 6 in with Seving bowl area of 5 in wide 2 In deep.

Great for condiments.

Shipping USPS advantage  2-5 days to save