THIS IS an attractive book about a now highly unattractive subject: the pursuit and killing for profit of one of the most intelligent mammals on earth. Dorothy Harley Eber began When the Whalers Were Up North (McGill-Queen's, 187 pages, $29.95 cloth) after showing a hundred- year-old photograph to a group of Inuit in Cape Dorset and being astonished when they recognized the Inuit hunter in the photo. "'This picture makes me remember the stories my grandmother told,"' said one man. Reasoning there must be many grandmothers (and grandfathers) still alive to recall the great days of whaling from the Inuit perspective, Eber set out in 1982 to find them. In all, 52 people were interviewed, some of whom drew pictures to illustrate their stories. The end result is a remarkable collection of Eastern Arctic lore. Eber also points out that the beginning of the end of the Inuit's own way of life is commonly supposed to have originated with the fur traders. In reality, it began with the whalers, who arrived in the north fully 50 years earlier.