Dear Yahya,
I believe if you put the verse into its context as follows:
O Children of Israel, remember My favor which I have bestowed upon you and fulfill My covenant [upon you] that I will fulfill your covenant [from Me], and be afraid of [only] Me. (40) And believe in what I have sent down confirming that which is [already] with you, and be not the first to disbelieve in it. And do not exchange My signs for a small price, and fear [only] Me. (41) And do not mix the truth with falsehood or conceal the truth while you know [it]. (42)
You'll find that its a commandment to the children of Israel to not conceal the truth or mix it with falsehood.(As Eliiah said). However, when it comes to books, movies, etc. One should simply stay away from those that go against the Quran's teachings. Like media that has obscene material.
Salam