Here's few tips to save time while working in ArcGIS:
1. To zoom to any layer’s extent: Alt + click on your layer name in the table of contents
2. To undo last edit: Ctrl + Z (also in Photoshop and other programs)
3. To rename any selected item: Click on the iteam, then press F2
4. (In Tables) to go to the first cell of your current column: Click on Ctrl + up arrow. Click on Ctrl + down arrow to go to the last cell.