First, the pawns clearly intended for player use: One for each of the iconic pre-gens, Ezren, Kyra, Merisiel, and Valeros. Also a set for use with the Box's basic character generation rules, one each for every combination of Cleric/Fighter/Rogue/Wizard, Human/Dwarf/Elf Male/Female, for 24 total--that's in addition to the iconics so there are, for example, two male human fighters if you count both Valeros and the generic "Fighter, Human Male."
There are also four sets of tokens for tracking actions, each including three action tokens (12 total) and a reaction token (4).
The Box does include stats for more monsters that are used in the included adventure--50 total--and they all have at least one pawn. These are helpfully color-coded with a dot on the lower right side, so you can distinguish any of the sets that have more than one.
The Medium pawns are:
Animated Armor (2)
Basilisk
Boar (2)
Bugbear Marauder (2)
Cat, Leopard
Centipede, Giant (2)
Doppelganger (2)
Dragon, Wyrmling Green
Drow Priestess
Drow Sneak (2)
Drow Warrior (3)
Elemental, Brine Shark
Gargoyle
Ghost Commoner
Ghoul (2)
Harpy
Hell Hound (2)
Hobgoblin Warrior (2)
Mimic
Ooze, Sewer (2)
Orc Commander
Orc Scrapper (4)
Orc Trooper (2)
Shadow
Skeleton Guard (4)
Snake, Giant Viper
Spider, Giant (2)
Web Lurker
Wight
Wolf (4)
Xulgath Boss
Xulgath Warrior (2)
Zombie Shambler (4)
The Large ones are:
Ogre Warrior
Owlbear
Skeleton, Skeletal Giant
Troll
The Small ones are:
Elemental, Cinder Rat
Elemental, Sod Hound
Elemental, Zephyr Hawk
Goblin Commando (2)
Goblin Igniter (2)
Goblin Warrior (4)
Gremlin, Pugwampi (4)
Kobold Dragon Mage
Kobold Scout (2)
Kobold Trapmaster
Kobold Warrior (6)
Rat, Giant (4)
Snake, Viper (3--these are actually Tiny, but the pawns are the same size as the Small ones)