What role do the spiders play in this chapter? What does the great spider do to Bilbo and what is his response? What heroic feat is Bilbo able to perform because he stays clear of the webs?

The spider impedes Bilbo's progress, but he's able to get free and he slays the spider. Bilbo stays clear of the webs, and he because he's wearing the ring and invisible, he leads the spiders away and is able to free the captured (ensnared) dwarves.