How much did you give him? A spoonful? Or a whole bowl full?
Sharing certain table foods in moderation isn't necessarily going to kill your dog. By moderation I mean a little spoonful once in a while. Not every meal, and not more than a bite or two. Those extra calories add up fast in dogs and cats, and obesity can be a big concern if you overfeed from the table.
And then there is the obedience issue. Feeding from the table encourages behaviors that many people dislike, but it is a personal preference. I don't particularly enjoy a drooling dog sitting near me, staring at my every move as I eat, but some people do. To each their own. My drooling/staring dog has to lay down in the other room while we eat. No begging allowed in our house.