There are always old women selling kiselo vrhnje and sviježi sir. Kiselo vrhnje is sour cream and sviježi sir means "fresh cheese". It's sort of like cottage cheese in the States, but without the curd chunks. It's smoother. You buy equal parts of both and mix them together at home, adding a good amount of paprika powder and freshly chopped garlic, and it's tasty. This is called "sir i vrnje" once mixed, "cheese and cream".
Sir i vrhnje.
The stuff sold at the market is usually homemade, they say it's domestic. So, the olive oil you get there is FAR, FAR tastier than what you buy at the store. And it's usually around $12-$15 for a one liter bottle, which is not bad for very high quality oil. The honeys are also produced by the guy selling them. There are various cheese sellers too, selling smoked and unsmoked cheeses of various sorts. A table is set up for selling lavendar flowers and those little lavendar pillows for your sock drawer. Various dried fruits are also available, with a large amount of figs. Local figs are really great.
In short, it's a better place to shop at for the stuff they carry than a regular store is. It's usually cheaper and of much higher quality, and you know you are handing money to the person who produced it or their agent.
The tržnica in Gajnice.
The interior area of "Dolac", the tržnica in the centar of Zagreb.
These women are selling "kiselo zelje", or "sauer kraut".
Inside, there's a lot more meat, fish and bread stalls.
Olive oil here on the right. The oils she's selling are great!