For sellers with Selling Manager Pro, you can get a download of a CSV file of your Active items. 

For sellers without SMP, you can use the relatively similar File Exchange Export.

If you have Selling Manager Pro:

1.  click the File Management Center link on the left of your Selling Manager Pro page. 

2.  click the Create a Download Request link. 

3.   setup a download for your Active items.

If you do not have Selling Manager Pro: check out this guide on 
How To: Use eBay File Exchange.