Hi, thanks!
The NPC behavior table: The top is a very shorthand reminder to myself. It says:
Disp: d 10A/6P, Ctx: @+A/-P, WH: Delta Ctx, SH: Delta Ctx & +/- 1
Ok, so when you make an NPC, they should have a Disposition of active or passive. This is how they tend to tackle things in life, sorta like introvert / extrovert. Some NPCs are calm and collected, I would say they have Passive disposition. Others are aggressive or energetic and spirited, I would say they have Active Disposition.
When rolling on the NPC Behavior, if they have an active disposition, roll with a d10. If they have a passive disposition, roll with a d6. Passive NPCs are "locked out" of some of the more active behaviors.
But along with their normal disposition, which you as a PC cannot change, NPCs also behave according to the current context (Ctx). Even a normally passive NPC might be very active in the current context of the scene. Their "activity" in this context specifies whether you roll with advantage or disadvantage.
For example, a friendly peasant NPC who wants to help you with your current issue might be an NPC with a passive disposition, but active in the current context. So you would roll a d6 with advantage. This will cause rolls to gravitate towards the action "gives something", which feels appropriate.
Now, an NPC's disposition is usually fixed, but you can use your system's social check to influence their activity in the current context. An NPC with an active disposition who is active in the current context has a good chance of wanting to start a fight (d10 with advantage). You could then do a Persuasion check (or whatever social check you have in your system) to try and calm them down. If you pass (or WH: Weak Hit in Ironsworn), you have the option of switching their context activity before the roll, such as rolling with disadvantage instead. If you get a "SH: Strong Hit (ironsworn), or perhaps a critical hit / natural 20 in D&D 5e", you can switch the context, AND you can do the roll and choose to add or subtract 1. This means that strong hits / critical hits essentially let you as the player choose between 3 results on the roll, depending on what your character wants to happen as a result of their passed social check.
As for the Random Tables, if you are referring to the ones under the name generator, I use the Person table when making a new NPC, I use the Object table for things like emblems on shop signs, Event gets used from the Quest generator, and sometimes I just roll Modifier + Idea whenever I am stuck.