How to select all the embedded charts on the worksheet
If you need to select all objects embedded into the worksheet, e.g. select all charts to adjust their size, press Ctrl+G and click the Special button or use Ctrl to select objects individually.
Press Ctrl+G to display the Go To dialog box.
Then click Special, and then select Objects.
This will select all objects on the sheet, not just the charts.
Another option is to select each chart individually. Hold down the Ctrl key and then click all of your charts to select them. This may be easier if you set the Zoom percent to a small number.