TLDR : Answer Summary
A Norwegian citizen currently on a 30-day visa exemption stamp in Thailand can extend their stay for an additional 30 days by visiting the local immigration office in Bangkok, specifically at IT Square Laksi, and paying a fee of 1900 baht. Required documents for the extension include the TM30 form obtained from your landlord or accommodation, your passport, copies of your passport's first page and entry stamp, a passport-sized photo, and the cash fee. Additionally, as a Norwegian citizen, you are allowed two free visa-exempt entries per calendar year, which can also be extended. If you decide not to extend, a visa run to neighboring countries like Cambodia or Laos is another option, with various transport options available.