Is there an in game real time automap in MM3 like the one in MM4 and 5? I'm talking about the on that appears over the "Might and Magic" logo in the upper right panel.
In MM4&5 you just click on the panel, and if you have a character with cartography, the automap appears and draws in real time as you move. In MM3, I have characters with cartography, but the only time I can see the map is if I use the M key to pause the game and bring up the larger, static map.

Good question. I think you're right that MM3 doesn't have this feature. You can use the Wizard Eye spell to draw the minimap, but it will show you everything around you, not just the squares you've visited.
Can anyone correct me?

No this is exactly how it works in MM3. Personally I love the Wizard's Eye anyway ;)