Combine whole wheat flour, 1/2 cup all-purpose flour, oats, brown sugar, undissolved yeast and salt in a large mixer bowl. Heat milk and butter until very warm (120° to 130°F). Add to flour mixture. Beat 2 minutes at medium speed. Add eggs and 1/2 cup all-purpose flour; beat 2 minutes at high speed. Stir in enough remaining all-purpose flour to make a soft dough. Knead on lightly floured surface (or in mixer using dough hook) until smooth and elastic, about 5 to 7 minutes. Cover; let rest 10 minutes.
Divide dough into 32 pieces. Form into smooth balls. Place on large greased baking sheet or greased baking pan. Brush tops with melted butter; sprinkle with oats if desired. Cover; let rise in warm, draft-free place until doubled in size, about 1 hour.
Bake in preheated 350°F oven for 15 to 25 minutes, until golden brown. (If baking rolls on baking sheet with sides not touching, bake 15 to 20 minutes; if baking in pan with sides touching, bake 20 to 25 minutes.)
TIP: Bake rolls ahead of time and freeze. To serve, thaw and rewarm in 250°F oven for 10 to 15 minutes. These rolls also make great mini sandwiches.