Most local markets I know of have at least a few stands that sell stuff other than food items. You need to inquire at the mairies of the towns you're interested in. Most street markets are organized by the town governments (even if they contract out some of the details to private companies).
The town hall will probably want to see your KBIS (business registration) or some other evidence of your business entity. It's possible that the mairies may only allow vendors properly registered with the VAT authority (this lets out AEs), though I'm not entirely sure of this.
Cheers,
Bev