Question

Fool! don't you see now that i could have poisoned you a hundred times had i been able to live without you meaning

Answer 1

Here the narrator means that she could have harmed the person many times but as the narrator can't live without that person she isn't doing that.

In brief it means :-
It is so easy for the narrator to do anything to that person but the narrator isn't doing it. The narrator meant poisoning in the sense harm. In the sentence" Fool! don't you see now I could poisoned you a hundred times had I been able to live without you" It shows how the narrator is attached to that person that the narrator can't imagine a world without that person. That person might be anyone but he/she is so important for the narrator. The narrator could do anything if he/she wishes but the narrator isn't able to do anything because the narrator knows very well that he/she can't live without that person. In the above sentence poisoning doesn't mean just contaminating the food with poison but it means that harming or troubling etc.

Hope this helps you : )

Answer 2

it means that the girl/boy could've killed the other person in one shot but the girl/boy did not because she/he  knew she would'nt be able to live without the person