All sorts of munitions were involved -
Including gardening tools! In the 1980s, my next door neighbour - a former farmer - showed me hand tools that he had been given under the scheme.
Lend Lease was a huge thing for the British, Most of us on this side of the pond probably don't appreciate just how big. All sorts of munitions were involved and all of them would be important over the course of time, but in 1940 Britain was being severely throttled by Hitler's U-Boats. The first, and perhaps most important, delivery, under Lend Lease was a batch of aging but still serviceable surplus destroyers to bolster Britain's escort capability for Atlantic convoys. Lend Lease tanks and weapons would also provide stop gap replacements for equipment lost during the fall of France and left behind in the Dunkirk evacuation. Britain believed a German invasion was imminent and British industry had no hope of replacing all of the losses quickly enough on its own.
Interesting - or maybe irrelevant historical note: this song (I found a George Formby version on Youtube) appears to be all about Lend-Lease as I suspected, so must date from the latter half of 1940. However, the label stock still says "Fabrique en Angleterre" on the right-hand side of the copyright company box despite there being absolutely no chance of a copy being sold in France..