I am going to ask the waitress if she doesn't mind telling the other table to keep their voices down.
Are they being too loud for you?
Yeah, it's a bit hard to enjoy my meal like this.
I'm sorry they're bothering you that much, and it's your right to make your experience as comfortable as possible.
The only thing I'm after is the noise.
Well hopefully the waitress is able to get the other table to cut the noise down a little bit.