In short, it's a term used to assert one's own opinion while cautiously acknowledging that the listener is of the same opinion.
Guy 1: I was on my ski-doo the other day and I saw a moose eating a bucket of poutine.
Guy 2: Fuck off, eh?
Guy 1: That girl has a big set of hooters, eh?
*Guy 2 is silent*
*Guy hands waitress a tip*
Waitress: Thanks alot, eh?
*Guy walks away*
Guy 1: There's some shit on your face, eh?
*Guy 2 beats the shit out of Guy 1*
Equivalent to the American "huh?" or "right?"
Usually used to prompt a person to respond to what was said. or to indicate a lack of understanding.
Dave: You're damn right.
2) Dave: The dog is red and the sky is grey.
Adding "eh" to a sentence can indicate the speaker's willingness to accept dissent or to invite further discussion. Has been referred to as an "articulated question mark."
The interpretation of "eh" as carrying meaning beyond other routine interjections (huh?) is supposed to be uniquely Canadian. "Ascertaining the comprehension, continued interest, agreement, etc., of the person or persons addressed" is how the Canadian Oxford Dictionary puts it.
"We could get a pizza, eh?" -- where 'eh' is 'if you would like to'
"I don't know about that, eh?" -- where 'eh' is 'but perhaps I might be convinced if you explained further'
"What's that, eh?" -- where 'eh' is 'I would appreciate, friend of mine, hearing your interpretation'
"The beer's cheap here, eh?" -- where 'eh' is 'so what would you like to do about that'
"It's after last call, eh?" -- where 'eh' is 'were you aware'
<John> Pass me a beer!
<John> Pass me a beer, eh?
<Tim> No thanks
<Captain John> Hand o'er the rum.
<1st Mate Tim> Aye!
"yeah it wasn't bad"