A Blending Fork is a fork with over-sized space between its tines and a thick, sturdy handle.
It can be used to cut and blend fat into flour, mix dry or wet ingredients, for serving meat, for fluffing rice, etc.
It may have the standard four tines that a table fork has; it may have up to six tines. The tines may be up to 2 1/2 inches (6 cm) long.
Simone Beck, who along with Julia Child and Louisette Bertholle wrote “Mastering the Art of French Cooking” (1961), swore by blending forks. 
 McMahan, Jacqueline Higuera. California Rancho Cooking: Mexican and Californian Recipes. Sasquatch Books, 2003. Page 202.