食 Shí means 'eat'
The usual word for 'eat' is 吃 chī these days.
Example: 食堂 shítáng 'dining hall'
Note the form this takes in simplified characters on the left; in traditional characters, it remains the same but with the last stroke omitted: 餃，月餅.
饺 Jiǎo 'dumpling'
饺子 jiǎozi 'fried dumpling'
饼 Bǐng is 'biscuit'
Example: 月饼 yuèbǐng