There is only one difference in meaning between the two:
In the first: "He give the boy a book", you are talking about any book as you have used "a", an indefinite article.
In the second: "He give the book to the boy", you are referring to a particular book as you have used "the", a definite article.
I should also mention that in English for the present tense you would say:
He "gives", not He "give".
If you were talking in the past tense you would say:
He "gave"