The two are currently shooting for Yeh Jawani Hai Deewani.
Rajesh Kaushal, who works at the cafe, told a newspaper: "We were told to book the tables and it was quite a surprise to see both of them."
He added that Kalki Koechlin and Aditya Roy Kapur were to join them later.
They ordered trout, pasta and cheese balls, said Raj Malhotra, the restaurant manager.
Sources at the resort where the entire team of the film is staying said that when director Ayaan Mukerji went to grab a quick bite to this cafe with the team on Sunday,Ranbir spoke to the manager.
He liked the cozy atmosphere of the place. The unit members also plan to do some sightseeing and paragliding in Manali now.