transfer apps from iPhone 4S to iPad 3 using iTunes 10 on a PC
If you want to simply reinstall the apps, look for the Apps tab in the iPad sync settings on iTunes, tick the boxes of the apps you want to transfer. If you want to copy your save files, etc. then try the following.

Note I haven't tried this 

When you reset your iPad or plug it in for the first time, it will ask you if you wish to restore from backup. Try choosing your iPhone 4S's backup if it's in the list.

Also, you can simply re-download from the app store on your iPad at no charge. Instead of a price tag, you will see an Install button.