A wholesale store, an analogue of Metro.
Before entering, you need to get a one-time card (or issue a long-term one, but this is not easy), only you will be served at the checkout using it.
For large purchases (especially for businesses), this is a good option. It is advantageous to take something only if you live in Pattaya all the time, otherwise it is unlikely that any tourist will need 6 packs of milk or several boxes of eggs. However, there are some products in Macro that you won't find in other stores. I like kimchi in a jar straight from Korea, the most delicious in the city is sold here.
The disadvantage is that you feel like you're in a warehouse — there are boxes lying around, not very clean, besides, the meat department always smells a few dozen meters away, to put it mildly, not the best flavors.