You could also import the Excel sheet as table or you could transform the entries into InDesign Tagged Text TXT file and import it formatted into InDesign. To get the tags you would have to design one entry with Para and Chara Styles and export it as InDesign Tagged Text, read out the tags for the paragraphs and make a transformation with text connection in Excel and import that transformed sheet into InDesign as tagged text.
...When I click on the preview I am able to click through and see each familys info. However, when I select "create merged document" it only does one family and then creates 3,000 plus blank pages with no info.
Known bug with the preview button, I'm afraid, and once the template file is damaged it stays damaged.
Copy the place holders to a new file and try again, but this time DON'T press preview. Just take a leap of faith and run the merge, which should only take a few minutes, and check that.