To run a market stall as a trader in the Netherlands, you need a market permit (marktvergunning).
Market permits are issued by the local municipal authority. To be eligible, you must be registered with the Dutch Chamber of Commerce (KVK). You can find all relevant conditions in the market by-laws of the municipality in question.
Please note: A market permit is not the same as a market trader's licence. You need a market trader's licence if you want to sell food or goods from a stand or van on or near a public road.