Actually, Paul wrote more books than anyone, taking up 2/3 of the books, but as far as actual writing, literature, words, sentences, etc. Luke, who only wrote two books (Luke and Acts) “wrote” more than Paul. It’s like saying I wrote seven 100 page books, when you wrote one book that has 800 pages, same size font, same size page etc. All in all, Paul wrote 25% and Luke wrote 27% of the New Testament.
Books by Paul: Romans, 1st and 2nd Corinthians, Galations, Ephesians, Philipians, Colosians, 1st and 2nd Thessalonians, 1st and 2nd Timothy, Titus, Philemon, Hebrews (the author of Hebrews is not identified but is attributed to Paul)
Luke wrote the book of Luke and Acts.