IMO, nah! I had it and I thought it was a waste of $$$!!!
Best way to prepare for histo is to put all the slides or pictures that YOUR school used into a "giant" powerpoint slides! It will be more useful as it tailors toward your school.
It's a good book, but Histo is VERY low yield on the Step 1 (I know of people who had almost no straight-up histo questions). Nevertheless learn it well wherever you're being taught since it will be foundational for histopath.