Lounge availability during Covid period may change without notice. So please plan ahead.
As a matter of policy you can bring one guest. Period. You may try your luck at entrance maybe you are lucky. If not you can try King Power lounge which is accessible to member. You can apply by top up your account for 2,000 Baht and use that credit to purchase things at their shops at airport.
(1.2) Royal Silk Lounge and Royal Orchid Lounge:
Present a boarding pass of THAI Royal Silk Class – no guest allowed
Present a boarding pass of Star Alliance Business Class travelers – no guest allowed
THAI Royal Orchid Platinum and Gold members presenting a boarding pass of THAI or any Star Alliance flight. One guest is allowed when departing on the same day of THAI or Star Alliance flights.
THAI Royal Orchid Platinum and Gold members presenting a boarding pass of Thai Smile Airways. One guest is allowed when departing on the same day of THAI or Thai Smile Airways.
Star Alliance Gold status cardholders presenting a boarding pass of THAI or any Star Alliance flight. One guest is allowed when departing same day on the same day of THAI or Star Alliance flights.
Star Alliance Gold status cardholder presenting a boarding pass of Star Connecting partner and a connecting itinerary of a Star Alliance flight. One guest is allowed when departing on the same flight with Star Alliance Gold passenger.
Any accompanying person over the age of two is considered a guest. Children under the age of two may accompany the customer to the lounge and are not considered as guests.
https://www.thaiairways.com/en/experience_my_thai/on_ground/Lounge_Policy.page