LEAD: The May Department Stores Company said yesterday that it had named John E. Toler Jr. as president and chief executive of its Hahne's New Jersey department store division.

She has an eight-year-old sister called Rebecca or "Becca," and a baby brother named John Phillip Ramsey Jr., better known as "Squirt."

The Direct Marketing Association in New York named John A. Greco Jr. as president and chief executive yesterday.

The Tampa Bay Devil Rays yesterday named John McHale Jr. as their chief operating officer.

In September, his office filed a lawsuit accusing N.Y. Catalog Sales and the man listed as its "principal," an Alabama businessman named John A. Gill Jr., of making "unlawful and deceptive" loans.

But it recently named John J. Phelan Jr., former chairman of the New York Stock Exchange, as its new chairman with an eye to enhancing its presence in the harmonization effort.

Mr. Bush named a successor on Jan. 2, 1997: John L. Hill Jr., a former chief justice of the Texas Supreme Court, state attorney general and secretary of state, and a Democrat.

His companion, a horse trainer named John De Stefano Jr., was in Saratoga for the summer racing season and, alone in the city, Mr. Costa began to chafe.

In naming John F. (Jack) Smith Jr. as chief executive, the G.M. board chose a career manager who is as much an outsider as G.M. could get without actually hiring from the outside.

In his will, Molson named John Molson Jr., Thomas Molson, William Molson, George Moffatt and Peter McGill executors.