The finger like projections which increases the surface area in small intestine are called villi.

Explanation.

The small intestine consists of many folds which are called as villi. Each villus (singular)/ villi (plural) is surrounded by many epithelial cells. Each epithelial cell consists of many more microvilli. Therefore, villi and microvilli (part of villi) dramatically increase the surface area in the intestine for the absorption of nutrients (Fig 12).

Fig 12 shows the anatomy of small intestine and villi