“Teppanyaki” (or “teppan-yaki”) is a Japanese cuisine where food (such as steak and shrimp) is cooked in an iron plate (“teppan”) in front of diners. The Benihana restaurant chain made teppanyaki popular in the 1960s.
   
Cho-Cho restaurant in San Francisco, California, was associated with Benihana and probably introduced teppanyaki to the United States in 1961. “CHO-CHO, 1020 Kearny (EX 7- 3066). Affiliated and importing the Chefs from the famous Benihana in Tokyo. Offering for the first time in the U. S. beef cooked in the shabu-shabu manner and teppan Yaki at Hibachi tables” was printed in the San Francisco (CA) Examiner on October 5, 1964.
   
   
Wikipedia: Teppanyaki
Teppanyaki (鉄板焼き teppan-yaki) is a post-World War II style of Japanese cuisine that uses an iron griddle to cook food. The word teppanyaki is derived from teppan (鉄板), which means iron plate, and yaki (焼き), which means grilled, broiled, or pan-fried. In Japan, teppanyaki refers to dishes cooked using an iron plate, including steak, shrimp, okonomiyaki, yakisoba, and monjayaki.
 
The teppanyaki grills are typically propane-heated, flat-surfaced grills, and are widely used to cook food in front of guests at restaurants. Teppanyaki grills are commonly confused with the hibachi barbecue grill, which has a charcoal or gas flame and is made with an open grate design. With a solid griddle-type cook surface, the teppanyaki is capable of cooking small or semisolid ingredients such as rice, egg, and finely chopped vegetables.
   
Origin
The originator of the teppanyaki-style steakhouse is believed to be Shigeji Fujioka of the Japanese restaurant chain Misono. The restaurant claims to be the first to introduce the concept of cooking Western-influenced food on a teppan in Japan, in 1945.
   
(Oxford English Dictionary)
teppan-yaki, n.
Etymology: Japanese.
A Japanese dish consisting of meat, fish, (or both) fried with vegetables on a hot steel plate which forms the centre of the table at which the diners are seated.
1970   P. Martin & J. Martin Japanese Cooking 80 (heading)  Teppan-yaki steak.
1970   P. Martin & J. Martin Japanese Cooking 80   Teppan-yaki means literally ‘iron plate grilling’. This type of cooking, too, is usually done in front of guests on a large, rectangular griddle.
1970   P. Martin & J. Martin Japanese Cooking 81   Teppan-yaki duck.
1972   Mainichi Daily News (Japan) 6 Nov. 11/6 (advt.)  A variety of foods including Teppan-yaki (meats roasted before your eyes on hot steel plates).
   
25 August 1961, The Times (San Mateo, CA), “Bright Lights” by Lloyd Johnson, pg. 20, col. 7:
Cho Cho Restaurant Is Japanese Food Favorite
With so many Japanese restaurants popping up in and about the Bay Area, it’s time to call attention to James Sakata’s Cho-Cho restaurant, which will be one of your favorites once you’ve tried the authentic Japanese cuisine. The Cho-Cho is justifiably boastful of its Tempura bar (one of the culinary marvels of Japan). Being located in the dining room, makes it possible to bring the incomparable deep fried (in a light batter) food directly to your table at the height of its taste perfection—the moment it comes out of the bubbling nabe.
(...)
The Cho-Cho is more than a local restaurant. It is associated with Tokyo’s Benihana, a “blue book” name in Japan’s “Who’s Who” in the restaurant world.
 
5 October 1964, San Francisco (CA) Examiner, Official Dine & Wine Review, pg. 16, col. 3:
CHO-CHO, 1020 Kearny (EX 7- 3066). Affiliated and importing the Chefs from the famous Benihana in Tokyo. Offering for the first time in the U. S. beef cooked in the shabu-shabu manner and teppan Yaki at Hibachi tables.
 
11 February 1966, Los Angeles (CA) Times, “Roundabout” with Art Ryon, pt. 5, pg. 9, col. 4:
Something new in Japanese food is teppan-yaki at the Bamboo House (7175 Sunset Blvd., just west of La Brea). Steak, chicken, and lobster are broiled at your booth on a panel of stainless steel in the center of your table. It is prepared by Japanese college boys in happi coats, making the Bamboo House the only Japanese restaurant in town with boys, rather than girls, to cook for you. “Teppan” means steel (or iron) panel while “yaki” is familiar to everyone who has eaten sukiyaki, teriyaki, or batayaki.
   
2 September 1967, Dixon (IL) Evening Telegraph, “Looking Around” by E. G., pg. 3, col. 1:
Our first experience at a teppanyaki (iron slab grill) meal was as guests of Jane and Ron Wills of Akasaka Misono…we sat at a large table seating six to eight people…center of table is a large flat metal grill in which a chef cooks the meal…the grill is heated underneath by a gas burner…we had salad, bean sprouts and kobe steaks.
 
11 October 1967, Milwaukee (WI) Journal, “Enjoy Ritual of DIning in Orient” by Dorothy Witte Austin, pt. 4, pg. 28, col. 2:
At the great hotels there are usually two Japanese style restaurants and one French. At Okura, one is an outdoor, teppan yaki, grill and bar combination which is roofed but open to the terrace.
 
9 August 1969, San Francisco (CA) Chronicle, “After Nightfall in San Francisco” by Hal Schaefer, pg. 34, col. 1:
ON A RECENT visit to San Francisco, movie and TV star, Barbra Streisand, learned about Teppanyaki stule of Japanese cookery at Benihana of Tokyo restaurant.
 
4 October 1970, Seattle (WA) Times, “New-type restaurant in Seattle reflects economic optimism” by Warren Mantz, pg. C12, cols. 1-2:
(Benohana of Tokyo.—ed.)
There is a chef for every tweo tables. They cook teppanyaki (or steel plate) style—on a steel plate over gas burners, set in one side of a table.
 
Google Books
13 November 1972, New York magazine, pg. 30, col. 1 ad:
TEPPANYAKI
Teppanyaki steak isn’t Kegon’s creation. But the classic taste we give it is. We use only prime beef — the finest. We cook it right at your table, with a masterful flair. And our sauces are something else again.
(Kegon, 80 East 56th Street, NYC.—ed.)