I'd say that несколько is above 2 and below 10. More or less.

Sometimes prefix не- (when stressed) has not negative meaning but a meaning of uncertainty. некто = someone, нечто = something, некоторые = "some of", некогда = "once upon a time" etc.

So несколько can mean several (uncertain quantity) or "in some uncertain degree", which is somewhat, slightly, rather.