A federal grand jury here has indicted a Detroit man on charges that he supplied up to 10,000 amphetamine tablets a week for illegal sale in Washington to a network of distributors whose payments for the drugs were forwarded to Detroit through Western Union Moneygrams.

The indictment, unsealed in U.S. District Court yesterday, alleged that Robert (Rick) Wilson of Detroit routinely dispatched couriers by airplane to Washington with quantities of the drug Preludin, known on the street as "Bam," which were then purchased for $4 to $5 a pill. Proceeds from the sales were then allegedly wired to Wilson in Detroit through Western Union, either by the couriers or the buyers, or were carried directly back to Detroit, the grand jury alleged in the 40-count indictment.

Four Washington men were charged in the indictment with allegedly participating with Wilson in a conspiracy to distribute the pills that were supplied by Wilson's couriers. Also charged in the indictment was a Detroit woman whom the grand jury alleged delivered large quantities of the pills to Wilson at a cafe he operated there.

According to the indictment, about $100,000, allegedly proceeds from the drug sales, was wired to Wilson in Detroit from March through September 1980.

Assistant U.S. Attorney George J. Terwilliger III said the indictment resulted from a continuing investigation into out-of-town sources for Preludin, which is used as an upper and as a heroin booster. The sole U.S. producer of Preludin voluntarily cut off wholesale supplies of the pills to Washington two years ago because of increased concern over the growing illegal use of the drug here.

Last June, five Washington-area men, described as longtime suppliers of the drug for illegal purposes, were arrested after undercover police staged a phony cut-rate sale of the pills in a Northeast Washington hotel room. The pills used by those suppliers were obtained in Philadelphia.

In addition to Wilson, the four Washington men named in the indictment yesterday were Walter (Little Tex) Smith, 45, of 1900 3rd St. NE; Premo L. Moody, 31, of 1344 Bryant St. NE; Joseph (Burly Joe) Williams of Northeast Washington, and William C. Coles of 1731 New Hampshire Ave. NW. Wilson, Smith and Moody were arrested early yesterday, while Williams is being sought by law enforcement officials and Coles is in jail on an unrelated case. The Detroit woman, identified in the indictment as Carol Armstrong, is a fugitive, law enforcement officials said.

The indictment described Smith and Williams as wholesalers of illegal Preludin and said Moody was Smith's lieutenant. Coles allegedly helped Wilson make arrangements for distributors in Washington, the indictment alleged.

In separate indictments, also unsealed yesterday, a Palmer Park man and his daughter and five other District residents, including Williams and his wife, Rebecca, also were charged with distribution of large quantities of Preludin. Charged with distribution and arrested yesterday were Theodore Bynum of 1907 Bender Ct., Palmer Park; his daughter, Lula Mae Howlett of the same address; Lawrence S. Frazier of 314 Allison St. NW; Alesia Earline Dorsey of 4015 Kansas Ave. NE, and Henry Lee (Pee Wee or Baldy) Bell of 1445 Otis Pl. NW. Rebecca Williams is being sought by authorities.

Smith, Moody, Frazier, Dorsey and Bell each pleaded innocent in court. The remaining defendants have not made court appearances.