In the new document, create that one node by a simple mouse click. This node will later (step 5) be added to the palette (in a new section that holds your own nodes/edges). Once it is in the palette, it can serve as a template for new nodes that you are about to create via the Excel import**.
**From your original question, I understood this: "[...] string that I import in as an attribute table." to mean that you are using the Excel import. I hope this is correct?
New labels that you create will use the currently active default placement, that's why they will end up stacked on top of each other. BUT, after you have created a new label, you can move it with the mouse to another location. (Just add and move them in turn.)
Tip: To be able to better select the newly added label, give it a longer text than the label that's already there.
As an alternative to moving the label with the mouse, you can also select the label and in the "Properties View" change the "Placement" (under the "General" section).