You first need to populate the Employee Enquiries grid before you can right-click and Customise Grid Columns.
To View data in Employees Enquiries:
Go to Payroll, Enquiries, Employee Enquiries.
Select From Employee or untick Single Employee to run for multiple employees.
Select the From Date and To Date.
Tick Include Unprocessed Transactions to include the current pay, which hasn't been closed.
Click View.
For more information on Employee Enquiries, review Employee Enquiries.