You can see a pie (or doughnut) chart view of a single column by clicking 'View as Pie Chart' in the Column Header Menu.
As with the main Pie Chart, you can create a threshold (as value or %), and manage labels positiion and the order of the slices.
Most columns show a simple count of distinct values (e.g. try 'Employee' column). However where there are multiple values for that column, AdapTable will automatically group them (e.g. try 'Invoiced' column).
If you want to see a pie chart for a subset of values in a column then simply select the cells you wish to see and select 'See as Pie Chart' from the Context menu.