Putting this in answer form only because it claimed my comment was too long....
You would have better luck with this question in Ubuntu's SE: http://askubuntu.com/
Your options will probably be limited but I wouldn't be surprised if there are a few open source solutions available outside of Ubuntu's Software Center. I've never dealt with the scanning of multiple slides in Ubuntu but I've had great luck with programs like Picasa and Shotwell for photo management/importing/scanning. Also take a look at Xsane - https://apps.ubuntu.com/cat/applications/xsane/ - which from what I can tell does support multiple scans but you'll most likely need to manipulate to get the desired result.
And if you're absolutely committed to using Ubuntu, you can always take the approach of using WINE with the Windows version of your Epson equivalent. As your scanner is natively supported in Ubuntu, there is a chance you can get it to work. Oh, and also don't forget about using a virtualized version of Windows for those one-off programs that don't have Linux support. Let me know what you find though; as a developer, I have been tempted to create my own Ubuntu app for some time now. Good luck.
One last link: https://www.youtube.com/watch?v=YwXabll7HLM