One of the earlier files I posted on the Shadow World thread was a master encounter table. I put a lot of work into it, included every creature, plant, herb, profession, race or group found in SW Canon products. These encounter categories include: weather, accidents, essence, flora, herbs, creatures, creature (unusual), humanoids, groups, sub groups, vehicles, professions, objects, structures, events, special.
It starts with an encounter category table divided into simplified environmental zones with sub tables depending on the result. It also has two aux charts for distance to encounter and attitude/behavior of encounter if applicable. With just these tables it is easy to randomly generate SW encounters on the fly, generate a quick NPC group or other random event or encounter.