Tennyson brings a lot of action into this end scene of Arthur's life. He makes Bedivere the most important character during Arthur's death by using vivid imagery and detailed dialogue. The reader gets to see that even though Bedivere lies a couple of times (hiding Excalibur instead of throwing it into the Lake), Arthur sees right through him and when he finally throws the sword in, trusts Bedivere again completely.
Because most of the poem is done with dialogue, the reader gets to see the personalities of each character develop, and gets to see how each deals with the fact Arthur is about to die.
