If you want to import an .xls file into mysql just once you can use an sql program such as HeidiSql or others and use an already made import script (note: if you go with Heidi you will have to convert to csv)
You can look up other programs on :google:
Another option, since it sounds like you are going to do this often, you can always OBDC connect to a mysql table with Excel. (I know you can do it with Access so I don't see why you wouldn't be able to do it with Excel) But it's a complex setup and not fast if you've never done it before. But once it is set up you don't have to worry about it much anymore.