Some people behave bizarrely in cafes. I find it fascinating.
In the M&S cafe in Manchester, a woman was standing with her arms outstretched across the aisle, touching two empty tables at once. Not sitting, you understand, but touching both tables. They were the only empty tables in the place. My sister and I came along with our trays and simply sat down at one of the empty tables. Here's what happened:
Woman: those are my tables.
Me: don't be ridiculous.
Woman: you can't speak to me like that!
In Pret a Manger (very busy, but no alternative), a friend and I found a tiny space at the 'bar' area after we'd bought lunch, but only one stool. I decided to be nice and let my friend sit. After a while, the girl next to me got up to leave and I said, "you don't mind if I pinch your stool, do you?", to be polite (let's face it, I didn't need to ask; she didn't own it, and she was leaving).
She said, reprovingly, "other people have been standing longer than you!", as indeed some had...on the other side of the cafe, miles away from her and oblivious of her recently-vacated stool. I took the stool anyway. Surely she was the ultimate table martyr (great phrase) since she was fighting the good fight on behalf of people she didn't even know! Bl**dy table prig.