From the Petrossian Newsletter FAQ:
How to serve it-Service and accompaniments
A special presentoir designed by Petrossian showcases our caviar with a truly elegant presentation. So as not to break the eggs, caviar should be spooned carefully onto lightly toasted bread or directly into the mouth with our specially designed Petrossian palettes. Serve fresh premium quality Petrossian caviar in its original perfection. Do not sprinkle with lemon or serve with chopped egg, onion, or sour cream. Save these garnishes for inferior grades of caviar.