Is it permissible for my husband to take the leftover meals from the hotel after they have been served to the staff, and bring them home?

The general principle is that it is not permissible for an employee to take leftover meals home, because they are the property of the company, and the employee's work is compensated by a fixed wage. It has been stated in fatwas by the Permanent Committee for Scholarly Research and Ifta' and by Ibn Uthaymeen that it is not permissible to secretly take food from work, even if the employer is stingy or the food will spoil, unless there is knowledge and approval from the company. It is permissible to take the food if the company is aware of it, or if the food will inevitably spoil.