This means "oops, I'm sorry, I made a mistake, please, forgive me". I.e., you insist on something, the person you are talking to proves you wrong, and you say «Γράψε λάθος, έχεις δίκιο». It's colloquial. I am sure there is an equivalent in English, but I just can't put my finger on it. It's something along the lines of "my bad", but not exactly.