Less likely in big pubs in towns & cities, but perfectly normal in smaller/back street type places, and village pubs.
My fav pub in town is a micro-pub, it's about twice the size of my living room*, it doesn't even have a bar, the landlord and/or landlady just floats about chatting to people & disappear out back to pour pints when needed. It's like its their living room, and everyone tends to chat with anyone else in there, lovely atmosphere.
My fav village pub is also lovely, go in alone & up for chatting, pop yourself on a stool at the bar, and you are soon chatting away to others.