well... I have done trips alone. So eating alone is the only option. In that case, I will be reading travel guide (last min reading) or taking pictures of my food.
I frequently chat with ppl sitting next to my table as well... I think I am weird. haha
i wouldnt really eat at a restaurant restaurant alone.. but I eat alone at "cha chaan teng" or noodle houses all the time.. eating alone in hk is actually pretty common