Better would have been, "How to Behave Like a Normal Human Being Who Cares About Others, Likes to Have Fun, and Wants to Remain Receptive to Any Benefits That May Come His Way."
But I guess, "How to Work the Room" is sexier.
As a non-native speaker, "Working the room" seems like a good abbreviation of "how to behave...". Is there another, shorter, more descriptive phrase you were thinking of?
Spending good time with nice people at an event isn't.
"good time" and "nice people" are not phrases I'd use to describe networking events. More important phrases to me are, "free food" and "open bar".
(And even if you just brush up your social skills, that can be helpful.)
I don't think it is a coincidence that the phrase is very often applied to politicians. In fact, I would venture to guess that politicians are the group this phrase is applied to the most often.
I'm not saying that everyone who "works the room" is a politician, and I'm not saying that all politicians are strictly self-serving individuals (yes, there are some good ones out there). However, there are enough examples of politicians to whom the phrase is applied, that it is often associated with them. There are also enough self-serving individuals to whom the phrase is applied that it helps to give the phrase a negative connotation.
And, obviously, there are quite a lot of individuals who have both the "self-serving" and "politician" categories covered.