First it depends upon yourputer power. Next that's about the size of the municipal data files I got from reel tape back in my WIREdata days (1995-1996). The source of the data was a Prime mainframe. At the time only mainframe systems dealt with that quantity of data. The best way to extract and convert this data at the time on a 9MHZ Dell running Windows 95 was to use C programming (easy Win I remember) and open and write one record at a time or collect records in a structure if extra steps (like seeking all grantors) were involved. This was very early Internet days. The idea of importing and using municipal data was very new and untested. Each county had its own system and administrator. So that meant each extraction task was a separate project. My senior programmer created a system to make it easy to go from one project to the next with minimal coding each time (function pointers). It's hard to answer this question without details about your workstation and its capabilities. I have used both Notepad and Excel to open and view large files. If it's just to extract data or change something in the file I would write a program that finds it and rewrite file with the modification because I am very familiar with file I my oldest of programming skills.