Is it permissible to accept gifts from someone who works in companies that sell alcoholic beverages, while he avoids selling or storing them, and is it permissible to eat and drink from his food when visiting him?

If your husband's maternal uncle does not sell intoxicants (khamr) and does not assist in their sale, then his salary is permissible (halal), and it is permissible to eat from his wealth and accept his gift. However, if he sells them or assists in their sale, then there is a haram (forbidden) portion in his salary, and it is disliked (makruh) to eat from his wealth and accept his gift, though it is not completely forbidden. If his entire work is related to intoxicants, then his entire salary is haram (forbidden), and it is forbidden to eat from his wealth and accept his gift, except in cases of dire necessity, provided it is spent on the welfare of Muslims.