“It’s Chockers” Means “It’s Packed”

In Australia, if you walk into a café on the weekend and every table is taken, someone might say, “It’s chockers in here.” It means the place is packed, not that anyone is talking about a physical obstruction. Chockers is informal Australian English for a place crowded with people or, more broadly, something filled close to capacity. SBS glosses it as crowded, while Cambridge lists chocker as a slang form of chock-a-block.

A: Shall we eat here?
B: It’s chockers. Let’s try next door.

It is stronger than busy in one useful respect: a café can be busy and still have spare tables, whereas chockers suggests that it is nearly full. The word belongs in relaxed conversation. In a formal notice, packed, crowded or full will be clearer. Australians may intensify it as absolutely chockers; very is usually unnecessary.

https://www.sbs.com.au/language/english/en/podcast-episode/minipod-idioms-bad-english-made-better/m4bml6t6f
https://dictionary.cambridge.org/dictionary/english/chocker