I read a sentence in a chapter named "The Rattrap" which was:
The men with the rattraps said not a word; he only sat down and helped himself to the food
I think "helped himself to the food" just implies that he ate the food but I haven't seen "help" being used in this way. So is this usage of "help" correct?
To help oneself to something is to take it, 'serving oneself', generally in whatever quantity one desires. This may be with permission or otherwise. Sometimes the emphasis is on the fact a person takes what they want, and sometimes the emphasis is that no-one else is "helping them" to whatever it was. The "unlimited quantity" implication can be removed by saying things like "help yourself to a drink", because the quantity is specified.
