A more energetic schedule for Soviet leader Leonid Brezhnev was revealed here tonight by a senior Soviet source, raising hopes that Brezhnev's talks with President Carter could be more substantive than previously expected.

The Soviet president and Communist Party general secretary will make wreath-laying visits to Soviet war memorials Friday after he arrives here by air form Moscow, He will attend the Vienna Opera Friday night with Carter.

These public appearances had not been reported officially by the Soviets earlier, with Soviet sources giving contradictory reports of whether Brezhnev would attend the performance of Mozart's "Abduction From the Seraglio" at the opera.

The Soviet source also said Brezhnev will deliver a "two or three minute address" after the SALT II signing Monday. His remarks will take up one typewritten page, the official said, and apparently will be the only extended remarks by Brezhnev, 72, to be televised during his stay here. Soviet authorities had refused adamantly to allow the traditional toasts at the two countries' state dinners to be televised, presumably because of Brezhnev's speech dificulties.

The Soviet delegation of about 500 includes Foreign Minister Andrei Gromyko, Politburo member Konstantin Chernenko, and Defense Minister Dmitri Ustimov. They will stay with Brezhnev at the Soviet Embassy in downtown Vienna. Workmen reportedly have prepared four suites for the Politburo members.

Brezhnev, who had his Rolls-Royce flown here several days ago by special Airoflot airfreighter, is said to have vetoed staying at the elegant but more remote residence of Soviet Ambassador Mikhail Efremov because it is too far from the Imperial Palace, the Hofburg, where the treaty will be signed.

Senior members of the Soviet delegation below Politburo rank will stay at the Imperial Hotel, where the Soviets have taken about half of the 160 rooms, including the three royal suites on the second floor. These cost up to $400 a day, bed and breakfast, according to manager Otto Heinke.