Vulcans didn't socialize. And the concept of a "picnic" on his home planet would have been seen as foolishly illogical. Unfortunately, he had spent quite a number of years among humans, and had learned to deal (and scientifically appreciate from a sociological standpoint) such events. That, however, did not mean he would have to make perfunctory conversation. He could always just be the observer. Spock was very adept at observing. Skilled in the art of watching from an unbiased distance.
And he would have continued his solitary existence in this peculiar city had it not forced him from the still immobile Enterprise hovering above the planet to the grassy park.
He glanced about at the various individuals. Strangers, most of them. A brow curiously quirked at the sight of a cat walking across a picnic table. He found that disturbingly unsanitary, but made no comment to that effect. Being a Vulcan he was not one to show much emotion, but he was a little put off by the landscape, which reminded him of the mission to Omicron Ceti III, the site of some most unsettling plant spores.
Eventually, he found himself walking over to the tree that the young blonde woman sat beneath.
"Quercus robur," he identified. Then he quirked a brow. "Fascinating."