"Gate Leg" drop leaf tables of this type are in what's called the "Colonial Revival" style. Colonial Revival pieces are reproductions of the original American Colonial items originally produced from 1620-1780. The Colonial Revival style became popular after the first Centennial of the American Revolution in 1876. At that time interest and demand for original Colonial & Federal furnishings was so great it outstripped supply. This caused large manufacturers to begin production of pieces in the Colonial style from the Jacobean to early Georgian periods.
This one is based on William & Mary style examples made during the late 17th century.The Colonial Revival style reached its peak of popularity when this piece was made during the second quarter of the 20th century. Today values for these pieces depends on their quality of construction, how close they follow original designs, and their overall condition, but most sell at auction for less than $200.00 in the current market.