In many parts of China, eating eggs during Tomb-Sweeping Day is as important as eating moon cakes at Mid-Autumn Festival. The Chinese folk belief is that eating an egg on Tomb-Sweeping Day will bring good health all year. In China, this custom has lasted for thousands of years.
The origin of eating eggs dates back to "Shangsi Jie" (a traditional Chinese festival). In ancient times, women who want to have babies after marriage often colored boiled eggs with different colors and put them into the river, and people living in the lower reaches of the river picked the eggs up and ate them. It was said that the more eggs were eaten, the greater the chance the woman will get pregnant. Today, people believe that eating eggs on Tomb-Sweeping Day will bring success.
Source: China Daily