The commissioner shall adopt rules, pursuant to RSA 541-A, relative to the form in which each operator shall keep the separate books and records of his business. Each operator shall keep the books and records for 3 years in such a manner to insure permanency and accessibility for inspection by the commissioner and his authorized representatives. The records shall be open for inspection by the commissioner or his authorized representative at all reasonable times. The commissioner or his authorized representative may enter in or upon any premises where sleeping accommodations are rented or taxable meals are sold to determine whether the provisions of this chapter are being obeyed, and may examine the books, papers, records, and premises of any operator for the purpose of determining whether the taxes imposed by this chapter have been fully paid.