Yep, Lenormands are traditionally small decks -- probably because the Grand Tableau was the standard way of laying them out, and that takes up a lot of room!
Village Witch is right about bridge size vs poker size. Standard playing cards (like Bicycle brand from the drug store) are poker size, for reference. Most of the older decks are closer to bridge size (more narrow). (The Blue & White Owls, the various Dondorfs, Carte Mundi, etc.) Good reproductions are often bridge size also.
Many of the recent, contemporary Lenormands are poker size, and I've always assumed it was because the size is easily available via small production printers that indie deck designers use.
I like both sizes, but there's something very pleasant about the slimmer profile of the bridge sized decks so those are my favorite.