I am (continued Sauti) acquainted with eight thousand and eight hundred verses, and so is Suka, and perhaps Sanjaya. From the mysteriousness of their meaning, O Muni, no one is able, to this day, to penetrate those closely knit difficult slokas. Even the omniscient Ganesa took a moment to consider; while Vyasa, however, continued to compose other verses in great abundance.

In plain words: Sauti says there are 8,800 extra-difficult verses that only he, Suka (Vyasa's son), and maybe Sanjaya truly know. Even all-knowing Ganesha had to pause to understand them. While Ganesha thought, Vyasa composed many more verses.