Well it all really depends on what you are 'inserting' into the database ... i tried inserting a CSV file that was about 25k rows and ... well ... lets say MySQL hated me So then I just opened it up in Excel, split it into 5 5k row CSV files and it worked fine.
Is the data already in CSV format (comma delmited?)? If so, all you need to do is import it into Excel and then copy x amount of rows onto a new spreadsheet, etc. and then just import them all individually ... make sense?
Very bad because it's really the best way to import large mysql database backup. If you can, ask SSH access to your host, even temporary. Or ask your host to do the import for you. It's quick to do...