Bergman’s picnics in The Seventh Seal [Det Sjunde Inseglet], are moments of relief in an otherwise deadly serious drama about death and the meaning of God.
When Block interrupts his game of chess with Death, he joins Jof (Nils Poppe) and Mia (Bibi Andersson) travelling performers, for a picnic-style lunch. for Block, a knight errant (Max von Sydow). Block, who is near death, is innocently served strawberries and milk which symbolize fertility and life. The picnic on the blanket is diametrically opposite Block’s chess match with Death, which, of course is no picnic. 
At a second picnic episode, Lisa, the buxom blond wife of the local blacksmith seduces Skat, an actor, while preparing a picnic lunch in his line of vision while he removes his makeup. She flirts, ogles, and spreads a picnic cloth, presenting her arse to him. She is fully clothed, but Skat takes her meaning. Moving close to her, they eat a chicken thigh but then run into the adjacent shrubbery.
See Ingmar Bergman. The Seventh Seal [Det Sjunde Inseglet] (1957). Screenplay by Bergman based on his one-act play Wood Painting [ Trämålning] (1956)