Question

why does the passage tell you about the swords Gandalf found in the troll cave these are not troll make they are old swords very old swords of the High Elves of the West Mike n they were made made in gondolin for the goblin Wars​

Answer 1

It was mentioned to explain the power of the trolls, being able to take over those with some of the best weaponry, and how brawn versus brawn did not work in this case.