HIGH ON THE LIST of invitations we do not plan to accept is the following from the back cover of Darkest Hours, by Jay Robert Nash (Wallaby, $8.95): "Stand on the deck of the Titanic as she sinks beneath the North Atlantic . . ."

If, on the other hand, all you want to do is read a six-page account of the loss of the noble, optimistic craft, with numerous anecdotes, and a few paragraphs about the 1898 novel, Titan , that foresaw the event with considerable accuracy, you will find it here, complete with pictures. Also five pages on Krakatoa, 6 1/2 on Vesuvius, five on the Hindenberg, a bit over four on the Triangle Shirt Waist Factory, shorter items on the Thresher and the Spring Hill Mine disaster.Besides its 630 pages of encyclopedia-style entries on these and similar catastrophes, there is a more complete 145-page catalogue at the end in smaller print, arranged in categories ("Major Air Crashes, Major Earthquakes, Major Floods . . .") and listed chronologically. Some of the emphases might have been different (the Biafra tragedy is chronicled in three lines of small print), but on the whole this is quite an impressive volume; so many things have gone wrong in human history, and so many of them are here. Gorey Details

THE SPECIALTY of writer-cartoonist Edward Gorey is the small subtly nuanced, exquisitely produced book with fine engravings and obscure (often menacing) Edwardian overtones in both text and illustration. These materialize with a comforting regularity two or three times a year, with a new one usually timed to serve as an ideal Christmas present for that strange, crochety uncle who is so hard to shop for. Much less frequent in appearance are the omnibus volumes which gather up a dozen or more of the little books into one capacious tome suitable for hours of happy browsing; there have been only two of them, and the second, Amphigorey Too (Berkley Windhover, $5.95), has finally made its way to paperback, where those whose tastes surpass their means can finally enjoy it. The contents run the Gorey gamut: cautionary tales about rather nasty children; mysteries and romances about willowy maiden ladies; rhyming alphabets with odd key words; sinister, unclassifiable animals; and everywhere, a touch of the macabre. The drawings (see illustration) are superb, as always. Originals

GREGORY McDONALD has been building a solid reputation in a highly specialized area of original paperback fiction: mystery novels about men whose names begin with "Fl." Two novels with a hero named Fletch have established McDonald as a reliable producer of a superior product, and now Flynn (Avon, $1.95) demonstrates that he can handle more than one kind of story, more than one kind of hero. Inspector Francis Xavier Flynn of the Boston Police Department had a strong secondary role in the second Fletch novel, Confess, Fletch (Avon, $1.75), and clearly earned a right to star in this new opus - an intricate tale (and very well told) that opens with the sabotage of a 707 taking off at Logan airport and also includes the theft of a boy's violin.

The disaster novel reaches some kind of ultimate in Firespill, by Ian Slater (Bantam, $1.95), in which two supertankers collide off the Alaskan coast, setting 2000 square miles of the Pacific on fire and threatening to turn the Pacific Northwest into a large cinder. Slater deals effectively with social overtones and small human details (riots in Tokyo; the destruction of a rose garden) as with the progress of the flames, wrapping pure terror in a very readable package. Back in Paper

Listed below in no particular order are some former hardcover books whose paperback appearance you may have been awaiting.

Roots, by Alex Haley (Dell, $6.95). For those who can wait, a less expensive mass-market edition is expected early next year.

"Our Crowd": The Great Jewish Families of New York, by Stephen Birmingham (Wallaby, $4.95). A trade paperback edition, considerably more readable and durable than the inexpensive Dell mass-market edition, which has been out of print for some time.

My Life on Trial, by Melvin Belli, with Robert Blair Kaiser (Popular Library, $1.95).