If they are in your itunes library, then yes you can easily sync them to the ipad.
Syncing is merely the process of connecting to the Mac and copying everything over from your Mac to the Ipad that you have chosen to sync. Some things may go the other way as well, but its not a complicated process.
From your first post, I think you may be confusing syncing with homesharing. With homesharing, your ipad can access your media in your itunes library via your wireless network. I.e. streaming it directly, rather than having to have a copy on your ipad.