Correct Answer: He said to me, "You can eat from my plate."

Solution : The fourth option is the correct choice.

The steps of conversion are as follows:

• The reporting verb "told" is changed to "said".
• The first-person pronoun "I" is changed to the second-person pronoun "you".
• The modal "could" is changed to its present form, "can".
• The third-person pronoun "his" is changed to the first-person pronoun "my".
• The words of the speaker are enclosed in the inverted commas.

Therefore, the correct answer is: He said to me, "You can eat from my plate."