Data Merge does a single frame for each record. It sounds like you've got it set also to do a single record per page, but you can do multiple records, but each record will remain in its own frame.
I think you may have better luck placing the Excel table directly. You can link it so it updates when the file changes, but unless you use table and cell styles you will lose any formatting you apply ing ID when you do an update.
Time for me to sound like a broken record. Data merge could be used for this but I don't think it was ever intended for such recurring publications like you are making. There will always be a lot of repetitive work that always will need to be performed after each update.
Instead, I think you should read up on using an XML workflow. Now, the XML out of excel needs transformed to be viable inside ID. But that is reasonably easy and can be done in an XML editor or upon importing into ID. Though it has been set aside for a time, I am making an example of a college course catalog for a customer. I'll see if I can finish it off by the weekend. If so, I'll post it to this thread.
Take care, Mike