Kamala market is not in Kamala every day. The market is moving around the west coast of Phuket following a fixed schedule and Wednesdays and Saturdays it is in Kamala. The other days in the week you can find it in the other beach towns north of Patong.
You will find the same goods as you normally find in a market in Thailand.
The market is not a tourist market but caters to the locals in Kamela.
You will still find a lot of tourist on the market. Some of them are just walking around to get a look and idea of what a traditional Thai market looks like.
Another part of the tourist is the ones who do the cooking themselves. Kamala market has a very nice selection of fruit and vegetables to a low price. Also, you can find fresh fish.
If you are in Kamala on a Wednesday I can only recommend a visit to the market whether you need to do some shopping or just want a look.
I have visited numerous markets around Thailand, also in towns where there are no tourists. Kamala market is a 100% authentic Thai market,