"The habitual longing to purchase, read, store, admire and consume books in excess" is the sub-title, something into which Raabe was lured by one store's "nimiety of overstuffed chairs." From late Latin, it means an excess.
Early examples are religiously inclined, then less so, as in some table- talk by Coleridge, whose view was that "there is a nimiety - a too-muchness - in all Germans."
The OED has it last used in 1892, when the Illustrated London News lamented the nimiety of modern poetry, "the tendency to dilute the general effect by repetition". A word to revive, sparingly.Reuse content