The British and French were preparing an expedition to land in Norway and march to Finland to assist the Finns in fighting the Soviet invasion of Finland in the winter and early spring of 1940.
When the Germans invaded Norway, this force ended up in Narvik in an attempt to defend northern Norway from the Germans. It was withdrawn when the Germans invaded France proper.
I suspect this phrasebook may have its orgins in that whole affair. I'm sure the author of the piece was indeed utterly clueless.
The Brits invaded Norway to prevent a German invasion (not, btw, a good idea), not to fight the Russians.
There is evidence that the real target was Swedish steel production. In any event, the pretext went away with the Treaty of Moscow on March 12. The British force (and don't forget the Poles) doesn't sail for another month.
When the Germans invaded Norway, this force ended up in Narvik in an attempt to defend northern Norway from the Germans. It was withdrawn when the Germans invaded France proper.
The forces in the Narvik area were withdrawn after Dunkirk. The Norway evacuation was June 4 - 8 according to a quick check of internet sources, and Dunkirk was wrapped up on June 4.