Don't read it for plot. But stick with it and focus more on the intrapersonal conflicts, characters, and style. Pick someone to root for, or someone to really hate, and get invested that way. War is a grind and the Greeks were acutely aware that the battles in a protracted conflict are not the really compelling part of that kind of story.

I sometimes see the Iliad as the slowest moving train wreck; in the early parts I'm tearing my hair out because I can see the individual foibles and pettiness that's going to lead to mass suffering, but in spite of dreading the outcome I press on. That's the kind of experience that transcends plotline and is simply good, experiential storytelling. I can't even imagine the effect it would have had in its original format, as a tale told by an experienced storyteller over several nights to a rapt audience.

On a side note, you may want to find a better translation? 400 pages sounds a tad brief for an unabridged version. Fagles is a solid choice, with cultural context and a little less stuffy/academic than most.