PHPMyAdmin doesn't have too many advanced importing features. However, MySQL itself has the LOAD DATA INFILE command that's quite robust. If you save your spreadsheet as a .csv file (comma-delimited), this should be no trouble at all. Importing address books, however, depends entirely on the format the program that wrote the address book uses. If it's sensible (e.g. you can open it in Notepad and understand it with some work), it shouldn't be any trouble either.
