Adding content to a database table during module install
As alternative of implementing hook_install(), if the module needs to be sure those data are present in the database before it runs, you can implement hook_enable(). The difference between those hooks is that hook_install() is executed once, when the module is installed; hook_enable() is executed all times the module is enabled, which happens also when the module is installed. Using hook_enable() requires you to first verify the data are not already present in the database before to write them.
Implementing hook_enable() is what the Forum module does to create the taxonomy vocabulary, and the taxonomy reference field it uses. (See forum_enable().)

Keep in mind that if you need to insert too much values in the database, then you should find another way to do it, as code taking too much time to be executed would cause a PHP timeout, and the code would not be complete the data insertion.
The alternative is using batch operations, or queue operations.