You can create groups in the addressbook for people you invite to meetings on a regular basis.

• In the Addresbsook, click on the arrow next to 'new' and you will see a drop down menu. 
• Select the 3rd option, 'Create new contact group'.
• Give your group a name, and select individuals from the global addressbook on the right and click on add. 
• You can also search for them in the find box.

Once you have a created a group, you can use the group name in any of the user search places, such as the sharing screen or attendees field when requesting a meeting.