Malory's collection of Arthurian materials is classified as chivalric romance, but with the romance downplayed significantly. Arthur grieves for knighthood more than for his queen.
Malory is not all that polished and often seems to be ad libbing, but he develops a powerful prose style gradually -- so much so that probably the entire tradition would have been lost without him. It would have died in France.
Malory is credited with:
As the long story winds down, Arthur recedes into a textual fog. Then we turn back to practical matters.
One might detect the autobiographical impulse surfacing in this passage:
And, as the Freynshe booke sayth, there cam fourty knyghtes to sir Darras that were of hys owne kynne, and they wolde have slayne sir Trystram and hys felowis, but sir Darras wolde nat suffre that, but kepte them in preson, and mete and drynke they had.
So sir Trystram endured there grete payne, for syknes had undirtake hym, and that ys the grettist payne a presoner may have. For all the whyle a presonere may have hys helth of body, he may endure undir the mercy of God and in hope of good delyveraunce; but whan syknes towchith a presoners body, than may a presonere say all welth ys hym berauffte, and than hath he cause to wayle and wepe. Ryght so ded sir Trystram whan syknes had undirtake hym, for than he toke such sorow that he had allmoste slayne hymselff.
(Malory, Works 333)
Garbáty, Thomas J., ed. Medieval English Literature. Lexington, MA: D.C. Heath & Co., 1984.
Malory, Sir Thomas. Works. Ed. Eugène Vinaver. NY: Oxford University Press, 1971.