A picnic was an outdoor meal.
The Fourth Doctor and Leela freed several Zygon prisoners whilst on a picnic on Shontaa. (COMIC: Rest and Re-Creation)
When Sharaz Jek proposed that the Fifth Doctor and Peri Brown become his best companions, the Doctor mocked him by saying that they should have picnics together. (TV: The Caves of Androzani)
Gilia encountered the Ninth Doctor as a child, while on a picnic with her parents and older sister. (PROSE: The Beast of Babylon)
Before they were married, the Tenth Doctor went on a picnic with Elizabeth I. (TV: The Day of the Doctor)
For their first date, Rhys Williams took Gwen Cooper for a picnic on a beach, not realising that it was in fact a nudist beach. (AUDIO: The Sin Eaters)
On 22 April 2011, the Eleventh Doctor had a picnic next to Lake Silencio with Amy Pond, Rory Williams and River Song. (TV: The Impossible Astronaut)
The Eleventh Doctor and Clara Oswald decided to have a picnic on an uninhabited planet, only to find that the planet they chose had already been colonised. (COMIC: Planet Void)
The Twelfth Doctor told Clara Oswald that he had once had a picnic on Thedion Four, but had to wear a gas mask due to the planet's constant acid rain. (TV: Mummy on the Orient Express)
River Song and the Doctor shared a picnic at Asgard. (TV: Silence in the Library, PROSE: Picnic at Asgard)