The two guys are digging a hole on the ground with a 铁锹

Tablet is something flat, rigid, made of stone or clay that is inscribed with some characters on it

tablet 石头或者粘土等制度的刻字的碑，牌或者匾

I found the tablet in the deep hole，but I can not understand the words on it，so I
think it says the...um...um，I still can not certain/sure，so the man in front of me，became angry，he shouted at me，can not you read？I pretend to understand it，at last ，I just said  “hey”