Gaming on NT 3.51 is pretty much out of the question. Nearly all Win32 games (even really old ones) require some form of DX (for which there is no support in NT 3.51).
Your system is fast enough to play Quake, but you need a different OS (95+ or NT4+), as DOS Quake won't run under NT and GL and win quake requires a minimum of NT4 (as they make use of DX).
NT 3.51 is fine for office work, web browsing and basic video playback, but gaming is a strict nono I'm afriad.