What he said...^^^^
Brownie is a good idea as it can be toothpick tasted.
Edit...you will need to check market regs for sampling a baked product...which you will have to bake. Where will it be prepared? Same thing for a cream cheese or sour cream dip. And if serving a dairy sample, it will need to be kept cold throughout the market hours. Lots of options for this...
Is there some way to make a sour cream or cream cheese dip with chips or crackers?
And have recipes to give with purchases. Simple computer printed page with 2 or 3 recipes...make sure your customers can make what you are sampling to them. Print 2 across the top and 2 across the bottom, cut in half...
You will run into all varieties of food allergy issues, and you cant solve them all.
If you do sampling of a sauce/dip, consider how to dispense using a squirt bottle so there is no dipping in the bowl....
Chips or a disposable taster spoon....
You should have ability for cash also. I used a 2 pocket servers apron with $1s on one side and $5/10/etc on the other. At the time, the salsa was $4, so most sales needed change. This was back in the day when internet was nonexistent or dial-up. Keep your money on you, dont have a cash box unless it is very protected, not sitting on the table. If your price is $7.00, make sure you have lots if $1 bills at least for the first few markets until you see how much is digital payments -v- cash.
At each sale, I put my tubs of fresh salsa in clear plastic produce bags that were purchased from my local grocery store on those big rolls. Customers walk around the market and other customers would see the tub of salsa and ask...'where'd you get that'....
I used to also bring extra plastic and paper grocery bags. Things have changed now for some markets, you cant use paper or plastic????.... but when I would see a customer carrying several jars or bunches of carrot and a cabbage, i would call them over and give them a plastic or paper grocery bag. Just a courtesy thing in the spirit of the market...
And then there is all the stuff of canopy, weights, wash station, table, chair,
Check out clear acrylic photo frames. Not really frames, they are free standing, can be positioned anywhere on the table, and you can slip in in a new price sheet or info sheet every week as your inventory changes.
Oh! I prefered to use black or neutral colored picnic table plastic cloth which is easibly wipeable with a bleach cloth. Look for it at any fabric store. 3-4' wide...by the length of your table plus 2-3' on each end.
Good luck and Have Fun!!!
SL