Is there a way to easily purge all of the invoices at once?

Is there a way to easily purge all of the invoices at once? We also would like a way to have invoices from a list of suppliers purged monthly.
The invoice we are reffering to are freight invoices that we manually land in MFCS but do not pay to the vendor because we have one large invoice we receive from them. These invoices are bogging down the AP Open Trade report and it is getting to the max lines in excel.

These are freight invoices that we manually land in MFCS, but do not pay to the vendor because we have one large invoice we receive from them.