Does the husband's saying "If you want it, take it," in response to his wife's request for divorce, count as a divorce, knowing that he had previously divorced her twice?

As long as you did not choose divorce and rejected it, your husband's statement "you are divorced" does not entail anything, whether he said it initially or in response to your question. This is because a divorce conditioned on your will does not occur until you explicitly utter it. Merely taking your belongings and going to your parents' house is not considered a divorce if you did not intend it as such. However, if your departure was without your husband's permission and without a legitimate Islamic excuse, then you are sinful. An explicit pronouncement of divorce counts, but for anything else, the presumption is that the marriage remains. One must avoid negative assumptions about a Muslim, especially between spouses.