The atmosphere at "Samba Carioca" is laid-back and those present are mostly executives for the French energy giant GDF-Suez, Brazilian bankers and bosses of multinational oil companies lured by Brazil's huge underwater oil reserves.
Carnival may be the biggest party in the world, but it is also a colourful networking venue for Brazil's business elite, complete with top-flight alcohol and first-rate food.
"This is the only exclusively corporate booth at the Sambodrome," the hallowed parade ground for the city's top samba schools, says promoter Alexis de Vaulx, a French businessman who built a successful furniture business in Brazil.
"Business people are in a hurry, here, they have eight hours to get to know each other, network. And since everything is at a standstill during Carnival, that's the only thing they can do," he adds.
The night parades of floats packed with beauty queens wearing huge headgear, body paint and little else mark the highlight of Rio's five-day Carnival extravaganza and are broadcast to a global television audience.
"The Rio Carnival is the greatest show on Earth and the one that lasts the longest," says de Vaulx, who founded the Tok&Stok furniture store chain in 1978 but later switched to the event management business.
"Compare this with Roland Garros (the French Open in Paris), where you pay more than $2,000 to watch a match. And you don't talk to anyone, except for 30 minutes while having a drink."
At the Sambodrome, individual seats cost around $2,500 a night, with a little discount for companies that buy large block of tickets for their staff.
On this particular night, there are 350 registered guests in the two-level, tastefully-decorated booth featuring bars, a massage parlor, a beauty salon and a stunning view of the sumptuous samba parades.
Waiters serve Perrier-Jouet champagne and caipirinhas, Brazil's national cocktail.
At the buffet bar, an abundance of salads and sushi. Then comes the hot dishes: duck cutlets with olive sauce, served with a chestnut cream-filled crepe and sea bass with a ginger sauce.
A Rio-based French chef, David Jaubert, is on hand to supervise operations while de Vaulx, wearing an immaculate white suit, chats with journalists and guests.
Last year, 60 per cent of the companies at Carnival were French, he points out. This year, they make up only 30 per cent of the guests.
"This is due to the economic crisis in Europe, but also to the fact that some companies are focusing their resources on Brazil's soccer World Cup next year," according to de Vaulx.
The samba schools and their sponsors routinely invite local and foreign celebrities to their Sambodrome's VIP booths to lend their star power to the parades.
This year, the VIP guests include the 26-year-old American actress Megan Fox, of "Transformers" fame, who was hired to promote Brahma Beer, a popular Brazilian lager.
Among other celebrities in attendance are United States TV reality show star Kim Kardashian and her rapper boyfriend Kanye West, "Men in Black" star Will Smith and South Korean pop star Psy.
So does anyone really do any business at Carnival, what with all the partying and dancing? Lois de Crevoisier, an engineer for the oil firm Perenco, says he and his wife are just there to soak up the ambiance.
"It's a way to maintain good relations; to say, 'We're happy to be working together and we want that to continue.' It doesn't go any further than that."