Yes, I have done.
I have been away for short breaks and been to concerts on my own too and have been so surprised how helpful and friendly some people can be - even to having a group of 20 somethings insisting on escorting me to my hotel as well as fetching drinks for me during the concert, when they found out I was on my own!
As far as meals are concerned, Certainly when I'm away, I have had meals on my own. If I have the choice of where I can sit, I'll choose a table at the edge of the room - I find that if I am seated by staff, you often get put at a table in the middle of the room!
I'm a people watcher so have a great time just watching others - often other people will ask to sit on the spare seats , and have chatted to many people - often to find they live not far from me!