Not quite sure what you mean, but with my limited knowledge of excel could
it be that you have put a border around the chart and the edges of the
border are still in the undeleted rows.  Try Format/cells/Border.

When you deleted all the rows behind them, the charts aren't deleted,
but shrink to a line in height. If there are not other objects on the
sheet that you want to keep, you can delete all the objects:

Choose Edit>Go to, and click Special
Select Objects, and click OK
Press the Delete key, to delete the selected objects

To work with specific objects, you can add the 'Select Multiple Objects'
tool to one of your toolbars:

Choose Tools>Customize
Select the Commands tab
Select the Drawing Category
Drag the 'Select Multiple Objects' tool onto one of your toolbars
Click Close

Then, click the Select Multiple Objects button, and select any or all
objects on the worksheet.