This is a problem of definition and theater.

"Hand to Hand combat" is usually a euphemism for "Close Quarters Combat", and the two are not truly interchangeable, but the latter often suggests or hints at the former. In terms of frequency, it truly depends on the where, whats and whys.

The Japanese army had an offensive infantry doctrine based on bringing the enemy into close quarters battle, at once disturbing the psychological and tactical equilibrium upon achieving a successful infiltration or flanking maneuver. The doctrine found early success during their initial conquests. If well co-ordinated, the speed and aggression, coupled with an attack all too often from unexpected, or highly restrictive terrain, resulted in squad-sized forces rapidly deploying themselves in the enemy flank or rear, where they could either destroy enemy positions with fire, or with the bayonet. Technically speaking, nothing in the Japanese doctrine truly demanded hand to hand combat, but the realities of war (a large, but underwhelmingly equipped Infantry platoon), indoctrination and terrain (consider: The approach to Singapore) would often result in the Japanese enveloping attacks ending in some sort of hand to hand combat. The Japanese also placed great stock in the psychological effect fighting hand to hand would have on an unprepared defender in an era of warfare that promised to do away with such close quarters fighting in its entirety.

For lack of space I'll limit myself to that example, but I will end it on this note; frequency of hand to hand combat was, as a general rule, far greater in the Eastern Front, China and the South Pacific. In terms of how 'usual' it was, well, relative to what? Relative to contemporary combat, then yes, it was highly usual.