Yep, there is a lot of irrelevant stuff. From memory, the major sections of the book:
There's a quite a few questions here and there that you wouldn't expect to ever see on an exam. That primarily might be due to the different nature of the questions, textbook questions are designed to teach and give you initial practice with the concepts.
Heinemann has quite a lot of those extra asides (physics in action or whatever they call it), you can ignore most of those, but they are there for a reason - broaden your understanding slighty, take a look at the big picture and remember that physics isn't all about doing exam questions etc.
For the actual core textbook paragraphs, again a lot of it there is to teach and explain concepts, provide context etc. - although a lot of the time it doesn't do a very good job of explaining. A lot of that stuff is worth reading and understanding. If this was the part of the book you're having issues with, do keep in mind that it is a textbook and not a condensed set of notes.
But yeah, if it was the questions you have problems with, then yeah, there are a few of them that are fairly irrelevant/tedious/annoying. The 'aside' bits can also be ignored if you want to.