According to this article a football team in Norfolk, England, could lose their rights to play on their home ground, 21 years after the death of the last surviving grandchild of Queen Victoria.
I’m not sure if the clause mention King Olav specifically by name, or if that is an interpretation made. Because King Olav was not a grandson of Queen Victoria, but a great grandson. The longest surviving grandchild of Queen Victoria, was Princess Alice, the Countess of Athlone, who died in 1981.
Out of the great grandchildren, King Olav was not even the longest surviving one. Carl Johan Bernadotte, Count of Wisborg is the only one of Queen Victoria’s great grandchildren still alive.
What sounds plausible to me is that the clause intended the grandchild of King Edward VII, in which case it is indeed King Olav of Norway.
It is a curious case, isn’t it?