“It’s a great opportunity to meet new faces and soak up the vibe and energy in the city,” said Isaiah Little, 29, a Newark native and supper club regular who organizes Newark First Fridays, an art and cultural event downtown. “I’ve developed partnerships here and definitely friendships. It sounds cheesy, but you really get to know people.”

The club’s growth has coincided with signs of a rebirth in a city whose population has been inching up after decades of sharp decline. Amazon this week announced that Newark was among the cities on its shortlist for a second headquarters. And, along with the many new locally owned restaurants, other recent big-name additions to the city include The Halal Guys, Whole Foods and Marcus Samuelsson’s restaurant, Marcus B&P.

The Supper Club has outlasted Mr. Martinez, who moved to San Francisco in 2015. He remains somewhat amazed by what he began, but not that it’s still going strong.

“There’s just something great about gathering for food with people you know and people you don’t know yet,” he said.

Rob Thomas, one of the earliest members of the club, now serves as its chairman and cheerful chief nudge on Twitter:

“Half off steaks at the Ainsworth. You should be here.”

“Do your taxes and then come to supper club. You gotta eat, right?”