The Nephite teachings had long emphasized that when the Messiah came, he would bring redemption. Jesus therefore declares that he had done so. That prophecy is declared fulfilled.
The personal meaning of that redemption is that all might come to God and repent, and be received. In this context, coming as a little child might be a reference to the fact that little children had to learn how to act, and now that the law had been fulfilled, the Nephites were as children, again needing to learn what they should do.
This is not the end of a chapter in the 1830 edition of the Book of Mormon.