I come to RHB for a few weeks every autumn, and have a stream of family and friends visiting. Went to La Fable a few times last year, and a few times this year, and it has been absolutely top-notch every time.
Pleasant ambiance (depending on your tolerance for Edith Piaf, of course), and excellent service. The menu isn't large, but every item any of my fellow diners and I have ordered has been excellent. Best duck I've had anywhere, marvelous steak, a coquille St. Jacques to die for, superb trout - the list just goes on, without a misstep.
Not cheap, but typical of the better restaurants in this town. As always, of course, you can make quite a dent in your wallet when you venture into the wine list, but that's also normal.
La Fable has become my top-of-the-list, must-take-people-here eatery in Rehoboth.