NONFICTION : ALONE TOGETHER by Elena Bonner; translated from the Russian by Alexander Cook (Knopf: $17.95; 270 pp., illustrated).

Elena Bonner aptly describes her hastily written book as “like family conversation around the kitchen table.” And like such table-talk, it is often gossipy and rambling, and assumes that the listener/reader is thoroughly familiar with the subject--the struggle of Bonner and her husband, dissident physicist Andrei D. Sakharov, against their oppressors, the Soviet regime and its “anonymous Peeping Toms.”

The book talks about Sakharov’s successful hunger strikes which induced Soviet authorities to allow family members to emigrate and to permit his wife to go to the United States for medical treatment. Bonner stresses not the brutality that the Kremlin inflicts on its domestic critics, but the petty harassments and the vandalism suffered by Sakharov and Bonner at the hands of the KGB in their exile in Gorky.

Yet Sakharov is a shadowy, secondary figure in this narrative; his own memoirs, smuggled to the West, are to be published by Knopf at a later date. Bonner carefully avoids any intrusion into what her husband is likely to present. The value of the present work lies in the candid portrait Bonner presents of herself, and in her impressions of the United States, where she wrote the book during her six-month visit.

Bonner emerges as a quick-tempered, sharp-tongued, fiercely devoted champion of her husband’s interests and her own views. With thinly disguised sarcasm, she attacks well-meaning friends, both Soviet and American, who she feels have not been sufficiently aggressive in supporting the Sakharov cause. She is dismayed that the Americans she met during her visit, especially some of Sakharov’s colleagues in the scientific community, are not, in her view, sufficiently informed about her husband’s trials and the dirty tricks being played on him.

Bonner’s persistent single-mindedness and her readiness to pounce on anyone not in full agreement with her views are a bit dismaying. But they do not tarnish her courage and devotion in the face of her own massive medical problems and the Kremlin’s perversity. It is a book well worth reading, if only, as she puts it, as a “postscript to Andrei’s memoirs.”