Oh! I know how to solve this one!

You'll need to adjust a PHP.ini setting. Ask your hosting provider where you need to edit PHP.ini settings. Their FAQ on their website could be a good place to start. Either you'll need to put the specific setting in a php.ini file, or in a .htaccess file. These will be in the root of the folder where your website is (probably public_html). The .htaccess file will already be there because of a Drupal installation (if you installed Drupal in that folder). Anyway, you'll need to add:

memory_limit = 12M if your host said you need to add it to a php.ini file.

(You'll need to create this file and upload it to your server via FTP since you're on shared hosting. You can make a text document on Windows and rename it to php.ini. If you create the text document and it does not have a file extension (like .txt at the end) you'll need to show file extensions.)
- OR -

php_value memory_limit 12M if your host said you need to add it to a .htaccess file

Good luck!