Settings from Avalon to WWI and II; ''Lusitania,'' by David Butler. New York: Random House. 578 pp. $17.95. The Burning Mountain, by Alfred Coppel. New York: Harcourt, Brace, Jovano-vich. 438 pp. $15.95. Goodbye Mickey Mouse, by Len Deighton. New York: Alfred A. Knopf. 337 pp. $14.95 . The Mists of Avalon, by Marion Zimmer Bradley. New York: Alfred A. Knopf. 876 pp. $16.95. Savannah, by Eugenia Price. New York: Double-day & Co. 595 pp. $17.95.

March 23, 1983

The theme of war has long been a favorite of novelists, and it has given us some of our most memorable works: ''Gone With the Wind,'' ''War and Peace,'' ''The Winds of War.''

Recent weeks have brought us a new salvo of excellent novels based on the battlefield - from the chivalrous days of King Arthur to the impersonal, bitter fighting of World War I and II.

In all of these, with one fascinating exception, the outcome of the battle, or the war, is already well known. So the excitement, the suspense, the drama, in these books come from the stories they tell about individuals struggling to survive under the most extreme conditions.

Lusitania tells such a story. Surprisingly, our attention is riveted not so much on the 1,900 passengers of that doomed ocean liner, but on the German U-boat captain who eventually sends a torpedo hurtling toward the ship.

Author David Butler is best known for ''Lillie,'' ''Disraeli,'' and ''Edward the Seventh,'' all turned into ''Masterpiece Theatre'' productions for television. ''Lu-sitania,'' however, can be more closely compared to a recent popular movie, ''Das Boot,'' which tells about a German submarine crew's struggle to survive as the war turns against its nation.

In World War I, submarines were crude, noisy machines, able to stay down for only a few hours, often quick victims of destroyers. Even so, they were ''gray sharks'' to freighters, oil tankers, and other vessels unable to defend themselves.

As students of history know, America, under President Woodrow Wilson, was determined to maintain neutrality with its key trading partners, Germany and Britain. Only 35 of the 159 Americans aboard survived. Although we know the facts, the author maintains the suspense right up to the last page. Butler's best writing, however, focuses on the German sub and its captain:

''He dived lower and put on speed, turning to port. But the angry buzz of the (British destroyers') propellers stayed on his tail. He took the risk of diving even lower, wheeled to starboard and cut all engines. No possible sound nor movement could tell the destroyers where he lay, yet they remained almost exactly above him.

'' 'How do they know?' Hirsch asked tensely.'How do they know?' ''

How did the British destroyers know?The answer to that is one of the better episodes in this action-filled book.

War is also the theme of The Burning Mountain. The author asks, What if? What if Harry Truman had not dropped the A-bomb on Japan? What if US soldiers and marines had been forced to fight it out house by house, street by street, city by city, all the way across Japan?

It's a question that has haunted many World War II veterans who were already preparing for the invasion when Hiroshima and Nagasaki were hit. Without ''The Bomb,'' US military and political leaders expected staggering casualties during an invasion.

Author Alfred Coppel, in a fine book, has captured the human story on both sides of what the ultimate Japanese-US battle might have been like. Coppel himself was a fighter pilot during World War II. His writing, based in part on actual war plans of both countries, pulls the reader through the pages with a story that grows steadily in power.

Already sitting on the best-seller list, Goodbye Mickey Mouse is also one of the best reads around. Simply stated, it's about World War II American flying aces stationed in Cam-bridge-shire, England - their friendships, their loves, their inner conflicts, all taking place while they're shooting the German enemy out of the sky. Len Deighton, who has penned 15 novels including ''The Ipcress File,'' ''Funeral in Berlin,'' and ''SS-GB,'' has written a captivating novel that's anything but ''Mickey Mouse.''

The Mists of Avalon currently sits a couple of rungs farther down on the best-seller list. Marion Zim-mer Bradley, in this overlong work, attempts to tell the often told story of King Arthur with a new twist - this time from the point of view of the women in his life. The story has been better told in the past, most notably by T. H. White, whose ''Once and Future King'' became Broadway's and Hollywood's ''Camelot.'' This book will probably be enjoyed mainly by enthusiasts of the Arthurian legend and readers who are inclined to get misty-eyed while watching TV soap operas.

Savannah is mentioned here because Eugenia Price's earlier ''New Moon Rising'' made the best-seller list. This one may also, but it shouldn't. The book fails because it is a costume novel, which in this case used the Savannah of 1812 for a backdrop. It could just as well have been set in pre-czarist Moscow or 1983 New York.