Nice place to dine and chat accompanied by some fresh oysters! They have a special for oysters on Mondays; $15 dollars for a dozen of Malpeque! You should expect the service to be kind of slow if you're ordering oysters on Monday.
I went last Monday and we weren't served until 40mins later. We kept telling our waitress that we've been waiting for a while; she apologized and told us it's a Monday and that it'll take some time. When our first round of oysters came, we placed another order for oysters and that came a lot quicker because the waitress made a note to speed things up. Our third round came pretty quick as well, so we were pretty happy in the end.
Definitely go to Diana's if you're a seafood lover!