Quite means not ''very'' but also not ''too little'', something like: this book is quite good. its less than ''very'' but more than ''little''. And we use ''rather'' with negative statements, like: this movie is rather horrible. and the other use of it is we use it when we are surprised the thing we are talking about is more than we expected, like: this house seems rather nice. The speaker thinks the house looks better than he imagined. Hope i could help:)