Why do we served with small plates in buffet ??

Whenever I attended a buffet lunch, I am always served with a small plate.. 

I always wondered, there are many things to eat and they are giving such small plates !!! 

 Why  ??? 

It is an optical illusion called Delboeuf illusion.

Every time we fill our plates, this illusion affects how much food we take and how much food we think we have taken.

As predicted by the illusion,  we

Under serve and over estimate in small plates.

Reverse is also true.

Suppose, we are served with a same dish of same quantity in two different plates,

One is small and other is larger, 

Then we tend to think that there is more food in small plate compared to the larger plate. 

But truth is that quantity of food is same   !!! 

This is the illusion. 

So  when served food in smaller plates, we actually eat less than we thought we had eaten. 

That's why in buffet, food is always served in small plates !!!