var actions = [
            { label: 'Show details', name: 'show_details' },
            { label: 'Delete', name: 'delete' }
        ];
        var columns = [];
        component.set("v.columns",[
            {label: 'Outbound call number', fieldName: 'OutboundCallNumber', type: 'Auto Number', sortable: true,},
            {label: 'Target Name', fieldName: 'Targetname', type: 'Formula', sortable: true},
            {label: 'Project Name', fieldName: 'ProjectName', type: 'Formula'},
            {label: 'Call Date', fieldName: 'CallDate', type: 'date-local', sortable: true , editable:true},
            {label: 'Phone Number', fieldName: 'PhoneNumber', type: 'Formula'},
            {label: 'Completed', fieldName: 'Completed', type: 'boolean', sortable: true},
            {label: 'Assign To', fieldName: 'AssignTo', type: 'Name', sortable: true,},

             {type: "button", typeAttributes: {
                label: 'Edit',
                name: 'Edit',
                title: 'Edit',
                disabled: false,
                value: 'edit',
                iconPosition: 'left'
            }}