If you want to change properties of multiple dbgrid columns, like 'sortable', 'searchable', etc. then you can do so by opening the property editor of the DBGrid Fields and the select 'bulk edit'. 




If you want to have all the checkboxes of a column selected or unselected, then select the row where the change should start and click on 'apply to all following'. It will then fill the lower column rows with the value of the selected column.