Administrators can give users permission to export data as an email, PDF, xlsx, etc, or to copy data directly from the grid. This can be done via profile settings, either for an individual user or in a system profile applied to multiple users.
Administration > Profiles
Administration > Users and select a specific user. Make changes from the 'Profile tab' on the user maintenance screen.
In both cases, go to the 'Export' section of the screen and check the relevant export options. The option named 'Clipboard' allows a user to copy data directly from the grid to paste into another application, e.g., Excel. Note there some limits on the size of the dataset that a user can export.
You need to have permission to edit user profiles to be able to change these settings. 'Profiles' and Users: Profiles'
Also see Assign profiles to users.