吃的盐比你吃的饭还多

吃的盐比你吃的饭还多

Literally means:

the salt I've consumed is more than the rice you've eaten

Actually means:

don't teach your grandpa how to suck an egg

It means that someone is well qualified and experienced.

Sometimes this phrase is used to show off the rich experiences or capabilities an older person has accumulated over the years.

形容一个人资格老，经验丰富。

有时用来卖弄老资格。常有夸耀的意味。