Table: Fix no data message alignment and table selector name (#77700)

* on multiple queries show no data message aligned + set a default table name for empty series

* simplify style

* check if there are fields

packages/grafana-data/src/field/fieldState.ts

@@ -31,7 +31,7 @@ export function getFrameDisplayName(frame: DataFrame, index?: number) {
   }
 
   // list all the
-  if (index === undefined) {
+  if (index === undefined && frame.fields.length > 0) {
     return frame.fields
       .filter((f) => f.type !== FieldType.time)
       .map((f) => getFieldDisplayName(f, frame))

packages/grafana-ui/src/components/Table/Table.tsx

@@ -372,7 +372,7 @@ export const Table = memo((props: Props) => {
               </CustomScrollbar>
             </div>
           ) : (
-            <div style={{ height: height - headerHeight }} className={tableStyles.noData}>
+            <div style={{ height: height - headerHeight, width }} className={tableStyles.noData}>
               No data
             </div>
           )}