When I've eaten alone (and I have many times in my life. Usually lunch from work, but also traveling and when I wasn't married), I haven't been bothered too much about the 'Are you eating alone?' and the horrified look of pity for the single middle-aged female who is all alone in the world. Since I AM married, I brush it off and smile. I always have a project with me, usually a book or a notebook.
I don't care for the bar option, as high chairs hurt my back and legs. I've left restaurants where the only options available are the high chairs.