A Manhattan doyenne is hosting a dinner party for a newly-arrived duke and duchess. Her husband, the guests, and their situations on the day of the dinner party are satirical lookalikes for the characters and plot lines in “Dinner at Eight.” The Chevrolets — rich rubes, the Talbots (a gallivanting doctor and suspicious wife), Miss Prantz — an aging burlesque queen, the host and hostess, and their daughter, who’s in love with an aging, egotistical actor to whom she sneaks lemons. The fun is in the parody.