Fuchsia Dunlop in the weekend FT nails it:
I'm an experienced solo diner. If the setting is right (ie, you don't feel self-conscious), then a casual meal with a magazine can be quite relaxing.
During solo portions of my travel abroad, I became well accustomed to wandering the streets of a random city and settling down to eat. One of my favorite memories is in Rome, my last night there. The heat all week had been oppressive and the lack of traffic laws raised my blood pressure significantly any time I tried to cross a street. (Here's my funny travel blog post on crossing a Roman street.) Tired but happy to be alive, I walked to a local restaurant, sat down by myself, ordered as much mozzarella cheese as I thought I could eat, and enjoyed watching the Italians at tables next me take hand gesturing to a whole new level.