An 84-member North Korean delegation arrived in the South Korean capital today to resume Red Cross talks, suspended 12 years ago, to help reunite 10 million families separated by the post-World War II division of the country.

Crossing the border at Panmunjom, the North Korean delegation of 14 delegates, 20 assistants and 50 journalists traveled the 35 miles to Seoul by car and bus.

At a press conference at the hotel, where the talks are to be held, North Korean chief delegate Li Chong Yul said he was "optimistic." He added, "If both sides display sincerity and understanding, I believe we can resolve all the problems to ease the pain of the separated families."

But, after paying a courtesy call on South Korean Red Cross President Yoo Chang Soon, the North Korean delegation leader complained about conference arrangements and without giving a reason canceled a scheduled visit to the 1988 Olympic stadium and family reunion plaza in southern Seoul.

Between August 1972 and July 1973, North and South Korean Red Cross delegations held seven alternating sessions at Pyongyang and Seoul. North Korea suspended political and Red Cross talks in August 1973.

Then last September, after North Korea sent an unprecedented delivery of flood relief to the South, the two agreed to reopen a dialogue, including resumption of the long-suspended Red Cross talks.

In January, North Korea abruptly canceled economic and Red Cross talks scheduled early in the new year, blaming the action on "provocative" South Korean war games set with U.S. forces for February. The problem was worked out, however, and the economic talks began after a five-month delay on May 17 at the Panmunjom truce village.

The Red Cross session, the 8th since the start of the family reunification talks in 1972, will be held Tuesday and Wednesday. The only agreements reached in previous sessions involved a five-point agenda on the whereabouts, visiting rights, postal privileges and actual reunification of separated families.