hi, yes you can have multi-RAB in case of multiple PDP context (i.e. connexion to different PDN, or to one PDN but with different qoS settings)
there will be one RAB (or more) per PDP context.
Having 2 RAB per PDP means that there are two flows of data related to the same PDN (I’m thinking : data + its “high-layer” signaling)
Anyway, that’s an area that I’m not yet familiar with, I hope I’m not telling too many mistakes 🙂
regards
pix