Ask whether Jabot Airport (JAT) has a lounge and the short answer is no: this small Marshall Islands atoll strip runs on inter-island service rather than the kind of flying that would ever need one. Jabot serves a small community on Ailinglaplap Atoll, and its coral runway exists to keep that community connected rather than to host anything resembling scheduled airline traffic with premium fares or genuinely connecting passengers.
Majuro is the honest place to start if you actually want a lounge-style answer for the Marshall Islands. Majuro International Airport, the country's main gateway on Majuro Atoll, is where Air Marshall Islands and the regional island-hopper service connect to longer-haul flights, and it is the only realistic spot in the country to look for any lounge facility at all, modest as that picture still is even there.
The reason Jabot itself has nothing comparable comes down to the airline-service picture. Flights into Jabot run on Air Marshall Islands' inter-island network, small aircraft hopping between atolls on a schedule built around cargo, mail, and essential travel rather than tourism or business traffic. That kind of service, valuable as it is for the people who depend on it, simply does not generate the passenger volume or fare mix that would ever justify a lounge on an atoll this size, no matter how the wider network eventually grows in the years ahead.
If your trip includes a stop at Jabot, expect a simple airstrip experience: an open-air or small covered waiting area, no food service to count on, and boarding straight onto a small aircraft parked on the coral apron. Treat any Majuro connection as the actual travel-planning moment that matters, and confirm inter-island schedules directly with Air Marshall Islands, since atoll flying adjusts around weather, tides, and demand rather than a fixed timetable, and seats on the smallest hops fill quickly around mail day.