I was reading Fleming's Casino Royale and ran into the following curious detail, when describing James Bond's meal:
Later, as Bond was finishing his first straight whisky ‘on the rocks’ and was contemplating the paté de foie gras and cold langouste which the waiter had just laid out for him, the telephone rang.
...
Bond shook himself, then he picked up his knife and selected the thickest of the pieces of hot toast.
He dipped the knife into the glass of very hot water which stood beside the pot of Strasbourg porcelain and reminded himself to tip the waiter doubly for this particular meal.
Now, from the text, it seems he's about to put foie gras on a toast. As far as I'm aware it's quite soft and not hard to cut with the knife and spread.
What exactly is the point of dipping the knife into hot water then?