No, the book of Job is not one of Theodicy, for Job never receives an explanation for his suffering (Ch. 40-41), which is the nature of Theodicy, justifying the ways of God to man. Rather, the “wager” (if that is even the right word for it), initiated by God, (1:8) sets up the drama to address the issue of what our response ought to be when faced with seemingly meaningless suffering. Job has done everything right; he is “blameless and upright” (1:1). God himself says that Job has done nothing to warrant his sufferings: “He still holds fast his integrity, although you incited me against him to destroy him without reason” (2:3).
What this does then, is dispels us of the notion that when we are prosperous it is because we are righteous (and vice-versa) and when we suffer it is because we have done wrong (and vice-versa). The book of Job shows there is no “quid pro quo” karmic relationship between our good deeds with prosperity nor our evil deeds with suffering.
Therefore, the reason God enters this “wager” with Satan is to teach both Job and the reader what the response ought to be to suffering (42:1-6), whether we understand it or not.