Thank you for your message.
Unfortunately its not possible to use scrolling text webpart with custom tables. They are not compatible with custom tables. If you would like this effect you will need to develop such functionality. I recommend you to find some jQuery plugin for scrolling text such as http://remysharp.com/2008/09/10/the-silky-smooth-marquee/
and then combined with our repeater webpart show data out of custom table and scroll it based on your needs. You can also inspire in our scrolling repeater webpart which you can find in CMSWebpats/Viewers/Effect/ScrollingText.aspx