Navigate to your Data tab at top. Select a Grid Category and Filter. 

Select the check mark header at top of far left-hand column to select all you'd like to apply the column edit on. Note that you will see all check marks in this row highlight green once selected.

Then, click on 'Edit Columns' in upper right-hand grey bar.

The choices on the left represent sections of the contact's profile you'd like added to your Grid search. You may click any one at a time and select to add more detail(s). The choices on the left represent your currently visible details shared in your Grid search. 

You may click the 'x' on any one to remove from your Grid search. In this image, you can see App Receive Date has been removed from the right-hand from the last image.

When you select a detail from the left, the box will grey out as such in this image below and you will see the detail available on the left-hand.

Click Save at top right to keep your choices and have them directly available in the Grid.

Once you click Save, you will be redirected to the Grid with your selected details available as additional columns (See App Receive Date added).

Next: How do I edit filters?