Failed Careers are great. PC's get a random failed career at character creation along with the items someone of that career would have possessed. It doesn't need to be said that they are wonderful mediums for implied world-building that immediately involve and inform players in and about the world.
When making failed career tables, I try to keep two things in mind. First, I try not to make the careers so specific that a player cannot immediately grasp the concept, take ownership of or define the career themselves. The world should be implied only. Secondly, making the weapon and item as interesting as possible. To play fast and loose with the definition of 'weapon' and 'item' - something a player wouldn't pick for their character off of an equipment list, something that isn't even on a equipment list. Interesting - as in strangely useful, producing new or odd situations - something that can be used for more than its intended purpose or even providing a narrative, character or adventure hook. You can fit a lot of flavour into [name], [weapon], [item].
While demographically unsound failed career tables can make for useful encounter tables. I like an exploding-d4 to determine numbers of an encountered career.
Below is an example failed career list for a place called Tetragrammatown. Read it and you will get a good feel for the setting via failed careers only.
Failed Careers of Tetragrammatown
Roll a d8 and a d6 (d86) to determine your character's backstory. The format is; [Failed Career/Backstory Name], [Weapon], [Item(s)]
12. Trench-Brother, sharpened shovel (as axe), permanently muddy military uniform.
13. Dare-to-Die Duellist, pistol with no bullets, black coat with white 'duel me' painted on it.
14. Riot Police, tear-gas grenade, plastic see-through shield.
15. Reluctant Zealot, cat o' nine tails, prescription rage-juice.
16. Living-Book, tattooing needle, an entire book tattooed onto body.
22. Puddle-Prophet, lead rod, electric pouring crucible.
23. Vehicularist, a pike (to prod people out of your way), a slow and primitive iron car.
24. Amateur Aeronaut, a helmet with a big spike on the top, a heavy wood and canvas gliding-suit.
25. Natural Philosopher, poisonous bug/plant/element (single use), specialist's tools.
26. Gruel-Giver, heavy ladle, keg of gruel (20 rations).
32. Clerical Assassin (official), crucifix with concealed dagger, mitre hat with pistol stitched inside.
33. Clerical Assassin (unofficial), poisoned needle, shabby imitation vestments.
34. Most-Wanted Warlock, pet anaconda, edgy eldritch tattoos.
35. Ratman Exterminator, rat-poison, vicious tunnel dog.
36. Puritan-Procuress, spanking-paddle, trunk of spare puritan clothing.
42. Arms Smuggler, pocket-rocket, fistful of solid rocket-fuel.
43. Prostitute Gangster, switchblade, fish-net stockings.
44. Old-Town Rioter, bag of bricks, knitted balaclava.
45. Wicked Noble, thumbscrew, flamboyant feather hat.
46. Atomic Fisherman, glowing harpoon, radioactive fish.
52. Political Congregant, swagger stick, a pamphlet listing the benefits of the new ideology you've invented.
53. Industrial Congregant, huge and consecrated spanner (as a mildly holy, two-handed club), sackcloth gasmask.
54. Itinerant Explosives Workman, big shard of shrapnel (as dagger), huge hand-cranked iron bomb that explodes instantly after three cranks.
55. Agrarian Congregant, ploughshare, emergency ploughshare weaponization kit and manual.
56. Book-Burner, single-use spray canister of napalm, slightly singed book (rolled randomly).
62. Latest Technology Inquisitor, electric cattle prod (target saves Vs paralysis or becomes slowed and loses 1pt of hp), EZ-lite bonfire with portable stake.
63. Authoritarian Thug, heavy hobnail jackboots for stamping, an imposing black uniform.
64. Industrialiser, single-use glue gun, furnace-powered engine (to glue onto something).
65. Morality Play Thespian, false metal god marionette (as flail), black renaissance theatrical costume and morph-suit.
66. Satellite-Botherer, laser pointer, tinfoil hat.
72. Penal Legionary, metal-pipe arquebus with 2 shots, black and white striped fatigues.
73. Faerie-Realm Polluter, oil drum full of chemical by-products, map of local fairy rings.
74. Dissolute Paladin, bejewelled knightly longsword, plastic bag full of bottles of laughing gas canisters and naughty printing-press pamphlets.
75. Involuntary Rocket Tester, molten weathervane, exhaust-blackened parachute.
76. Indentured Window-Washer, 100 foot pole, bucket of caustic soaps.
82. On-the-run Potationist, blinding bath-tub gin, backpack distillery.
83. Puritan-Bothering Pacifist Revolutionary, fruity trombone, book of jokes.
84. Satirist/Polemicist, razor sharp wit (0 damage), head and arms locked in a pillory/stocks.
85. Noir Detective, Colt Detective Special Revolver (d6 bullets), chainmail lined imitation trenchcoat (+2 AC).
86. 'Self-Abusing' Flagellant (get it?), stinging-nettle cat o’ nine tails, creepy adult toy made to a medieval standard.