To keep an area of the Data Model visible while you scroll to another area in the Power Pivot window, you can lock specific columns in one area by freezing them.
In the Power Pivot window, select the table that contains the columns that you want to freeze.
Select one or more columns to freeze.
Click Design > Columns > Freeze.
A frozen column moves to the front of the table. Additional columns that you freeze are positioned next to the first column that you froze. If you later unfreeze the column, it will not be moved back to its original location.