Okay, things are partially working now.
I created 3 different STBLs one for male names, one for female names and one for family names.
In the male and female names I've grouped names by decade so I can specify in my config which group to grab from (for example AbsNames1940s or AbsNames1950s)
The text I imported from looks something like this...
<KEY>AbsNames1900s/MaleName:Name0</KEY>
<STR>Aaron</STR>
<KEY>AbsNames1900s/MaleName:Name1</KEY>
<STR>Abe</STR>
...
<KEY>AbsNames1900s/MaleName:Name1287</KEY>
<STR>Zack</STR>
<KEY>AbsNames1900s/MaleName:Name1288</KEY>
<STR>Zeb</STR>
<KEY>AbsNames1910s/MaleName:Name0</KEY>
<STR>Aaron</STR>
<KEY>AbsNames1910s/MaleName:Name1</KEY>
<STR>Abe</STR>
...
The FamilyName STBL only has one set of names but it has been keyed with a string to localize and date it so I could make more in future. (The string I used is AbsNamesENC1990 to indicate names from the East North Central Part of the US from the 1990 census)
<KEY>AbsNamesENC1990/FamilyName:Name0</KEY>
<STR>Aaron</STR>
<KEY>AbsNamesENC1990/FamilyName:Name0_Female</KEY>
<STR>Aaron</STR>
<KEY>AbsNamesENC1990/FamilyName:Name1</KEY>
<STR>Abbott</STR>
<KEY>AbsNamesENC1990/FamilyName:Name1_Female</KEY>
<STR>Abbott</STR>
...
I started a new games killedallhumans. And plopped in a single sim. As NPCs were generated, I was disappointed to see a papergirl named "Christie Lively". I do not have "Lively" in my last name list...
But as sims were generated for coworkers, etc. Things started to look up as the names were plucked from my STBLs. But then another dissapointment occured.
I had specified AbsNames1940s in my config, and a sim named "Jammie Lockhart" appeared. "Jammie" only appears under AbsNames1970s and shouldn't have been selected.
I still wonder If I'm packaging the STBLs correctly, and if NPCs use these packages at all.