How do I get rid of my dinner guests when they linger round the dinner table seemingly wanting to leave while I am getting more and more tired and wanting to go to sleep?

What I always do is to retire in the bedroom and change into my pajamas. I then reappear at the table declaring that I am going to bed and that those who want to go can go, and those who want to stay can stay, with the last person making sure that the front door is closed. This usually has the immediate effect of everyone being embarrassed and getting up to leave. It is so much better to make your guests be the last to feel embarrassed and not yourself.