DLC

There were 20 pieces of downloadable content in total: 1 single player optional tomb, 4 multiplayer maps, 6 outfits for Lara Croft, 5 skills, 4 additional multiplayer characters. 

Interestingly, there were once DLC content from a Hitman: Absolution crossover however the Hitman franchise changed publishers in 2016 and so this content is now not available.

Tomb of the Lost Adventurer
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix
PRICE: £1.99 | $2.99
STORE DESCRIPTION: ​Explore the final resting place of an intrepid adventurer, and solve a puzzle involving a crashed plane to claim your reward.
01 - Tomb of the Lost Adventurer
Pick-ups: Salvage
Goal: To maneuver the airplane in order to use it to reach the chamber above
Location: Coastal Forest

Multiplayer Maps
01 - 1939 Multiplayer Map Pack
RELEASE: 3 April 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £2.49 | $3.99​
STORE DESCRIPTION: Wartime Bunker: Dating back to the World War II experiments conducted on the island, this bunker is a deadly maze of brick and mortar that could easily become a tomb.
Forest Meadow: This forest meadow is a hunting ground, filled with open spaces that can be advantageous and dangerous at the same time. Who is the hunter and who is the hunted?
02 - Caves and Cliffs Multiplayer Map Pack
RELEASE: 23 April 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £2.49 | $3.99​
STORE DESCRIPTION: A massive network of caves.
Cliff Shantytown: This settlement was built high in the island cliffs.  Its many layers hide some of the deadliest traps on the island.
The Burning Village: A fire has erupted in an abandoned Japanese village. The burning buildings offer multiple ways to escape your enemies.
03 - Shanty Town
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £1.99 | $2.99​
STORE DESCRIPTION: Shanty Town Multiplayer Map: This ramshackle area features steep climbs, multiple ziplines for quick escapes, and deadly traps to set for your enemies.
04 - Shipwrecked Multiplayer Map Pack
RELEASE: 7 May 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £2.49 | $3.99
STORE DESCRIPTION: Lost Fleet: A massive beached ship serves as a dangerous battleground filled with twists, turns, and traps.
​Himiko's Cradle: This temple is carved out of the solid rock of a mountain. Full of twists and turns, the scavengers have overrun this place, corrupting its once stunning beauty, and have placed deadly traps and zip lines. Stay sharp, the threats are everywhere.

DLC Outfits

These outfits were only available in the single player story.
01 - Aviatrix Skin
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99
STORE DESCRIPTION: This outfit dresses Lara up as a classic 1930s adventurer, bomber jacket and all.
02 - Demolition Skin
RELEASE: 7 May 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99​
STORE DESCRIPTION: Outfit Lara with the Demolition Gear, featuring an engineering jumpsuit and belt pack.
03 - Guerilla Skin
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99​
STORE DESCRIPTION: This outfit makes Lara look like a jungle warfare guerilla.
04 - Hunter Skin
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99​
STORE DESCRIPTION: This outfit camouflages Lara in a heavy coating of mud, action movie-style.
05 - Mountaineer Skin
RELEASE: 7 May 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99​
STORE DESCRIPTION: The Mountaineer outfit features the padded vest, grapples, and harness of an expert climber.
06 - Sure-Shot Skin
RELEASE: 7 May 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99​
STORE DESCRIPTION: With the Sure-Shot outfit, Lara wears a competition style archery suit with high boots and forearm guards.

Single Player Skills

All of these skills can be unlocked naturally throughout the game but it is possible to buy them to gain them earlier.
01 - Agility Skill
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99
STORE DESCRIPTION: The Agility skill lets Lara ascend mountain faces more quickly and ensures she lands safely from higher falls.
​02 - Animal Instinct Skill
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99
STORE DESCRIPTION: The Animal instinct skill lights up XP-laden animals in Survival Instinct mode, to help Lara upgrade more quickly.
03 - Headshot Reticule Skill
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99
STORE DESCRIPTION: The headshot reticule lets Lara utilize her weapons more accurately. When used with the pistol silencer, it makes for a deadly combination.
05 - Pistol Silencer Skill
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99
STORE DESCRIPTION: The pistol silencer lets Lara use stealthy tactics to overcome even the trickiest of situations.
04 - Pistol Burst Skill
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99
STORE DESCRIPTION: The three-shot burst pistol upgrade lets Lara unleash a hail of firepower on her foes.

Multiplayer Characters
01 - Fisherman
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99
STORE DESCRIPTION: The stalwart crew Fisherman.
02 - Scavenger Bandit
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99
STORE DESCRIPTION: The crafty Scavenger Bandit.
03 - Scavenger Executioner
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99
STORE DESCRIPTION: The deadly Scavenger Executioner.
04 - Scavenger Scout
RELEASE: 26 March 2013
DEVELOPER: Crystal Dynamics
PUBLISHER: Square Enix​
PRICE: £0.59 | $0.99
STORE DESCRIPTION: The wily Scavenger Scout.