This 8mm vintage home movie shows Christmas celebrations with a family in 1966 in their home in Onslow square, London.
There was no real detective work needed to find the location and event this film depicts because the reel has written on it, 'Christmas 1966, 81 Onslow Square'. All I had to do was google Onslow Square to find it is a rather prestigious road in London sandwiched between Chelsea and South Kensington. In 2020 the property is divided into flats and although it could have been a single house in 1966, I suspect that was it was individual flats at that time also.
I don't know who the people are in the film, but living in such a prestigious location it would probably be possible to find out with a bit more detective work. I suspect it may be a larger gathering than a single family because there seem to be two older couples, so it could be a wider family, or family and friends as is normal at Christmas.
Christmas 1966 film
The film is divided into two halves with the first run through the camera being a recording of the Christmas meal, and the second half taken in the drawing room as presents were handed out.
The scene in the dining room doesn't pan or move much, if at all, so I suspect the camera was placed on a tripod and left running as the family pulled crackers. When the family moves into the drawing room a light on the camera was used to illuminate the scene, and there is more camera movement about the room so I guess this section was taken with someone behind the camera.