Restore one table from SQL Server data file (.mdf)
Yes, the easiest way is to attach the MDF (if you can). Not all abandoned MDF files are attachable, it depends on how they were detached and what state the server was in when that happened. The proper way to take a backup is BACKUP DATABASE.

There isn't a way that I know of to extract only a single table from a detached MDF file, unless you're really, really comfortable with a hex editor.

So I think you are on the right track - attach your MDF as a different database name, and extract the data from the one table you need. Shark provided the syntax you'll need. However, again, a disk image does not necessarily leave an MDF in a usable state, so without a proper backup, all I can do is cross my fingers for you.