This is a traditional Thai snack called miang kam [เมี่ยงคำ], which supposedly had its origin around North Thailand in ancient times. Due to its simplicity, I can easily visualize people eating this snack ages ago. All you do is take some large, chaapluu leaves [ช้าพลู] to wrap the ingredients up before popping it in your mouth. From wikipedia:
The origin of the name is in “eating many things in one bite”; from “miang” (เมี่ยง), meaning “food wrapped in leaves”, and “kham” (คำ), “a bite”
Eating all the ingredients mixed together can give you quite a sensation with the mix of flavors. The leaves themselves add a slightly bitter taste to the mix.
This ingredients you put in the leaves can be any combination you want. On the plate there is (clockwise from 12): roasted coconut shavings, lime, tiny dried shrimp, red onion, ginger, more lime pieces, and in the middle are peanuts. You actually put in a little piece of lime like those at back, rind and all, because you want a little bit of that bitterness. Once the leaf is full of what you want, you spoon on some very sweet palm syrup. The palm syrup also has fish sauce in it to add saltiness. You can also add freshly diced chilies if you want some spice or green (raw) banana with peel if you want some bitterness. Lastly, close up the leaf and try to pop it in your mouth with out making a huge mess.
All in all, miang kam is a fun activity with a tasty result. I tend to avoid the ginger, banana and chilies, but everything else is good.