This is a vintage James Kent "Du Barry" Longton porcelain small tray, likely from the 1940s. It's characterized by:

Dense, all-over floral design, a style known as chintz.

The "Du Barry" pattern, introduced in 1934 and produced until 1980.

Multicolored floral motifs with gold accents.

A scalloped edge.

Small size, with a width of approximately 8 7/8 inches.