Christian Scheider, an actor and filmmaker from Sag Harbor, is hosting three screenings of films by Jacques Tati at the John Jermain Memorial Library in that village starting Wednesday at 5 p.m. with “The Big Day.” Tati, who died in 1982 at the age of 75, was a French comic actor, writer, and director whose recurring character was Mr. Hulot, a self-effacing man at odds with modern society.