These verses might be a little bit intense for your children. But they might get a kick out of them as well. You could have them draw a picture of Coriantumr and Shiz doing battle. But I wouldn't recommend having them act out these verses.
Make family scripture time productive. Get the kids excited. If kids can see how the Book of Mormon applies to them and if reading the Book is FUN, you might hear, "Is it time to read yet?", rather than, "Do we have to?" We are counseled to SEARCH the scriptures, not just read them. It takes preparation to do that with children. This is the preparation that I've done. Now I have it for reference next time. And you do too. Comments welcome.