This small Belleek dish may not be the typical piece since it is rather heavier than the best Belleek. However, it is a useful piece as a nut dish or for similar use. The brown (7th) mark dates the piece to the period 1981 to 1992, so it is not particularly old.
You can roughly date Belleek with this reference and note that the 3rd through 6th marks have a registry number that allows the design to be dated to its first year of use.