There is also an Import Text Gramplet add-on.
Once you had a sheets with recognized header for each object type, you could do all sorts of fast imports.
For instance, a hierarchy of Place objects for “Baldwin Township, Allegheny County, Pennsylvania, United States of America”:
Place,Title,Name,Type,Latitude,Longitude,Code,Enclosed_by
[P00001],United States,United States of America,Country,39.76,-98.5,,,
[P00002],"Pennsylvania, United States",Pennsylvania,State,40.8,-77.7,,[P00001],
[P00003],"Allegheny, Pennsylvania, United States",Allegheny County,County,40.46883,-79.98119,,[P00002],
[P00004],"Baldwin Township, Allegheny County, Pennsylvania, United States of America",Baldwin Township,Township,"40°22'48.54""N","80°00'51.44""W",15234,[P00001]
If you wanted to fork the Import Text Gramplet and hack the fork to recognize tab delimiters as well as comma delimiters, you could copy’n’paste directly from a spreadsheet. (With comma delimited, you have to do the “Save As” in the spreadsheet and then the “Family Trees → Import…” file shuffle with all the dialogs in & out. That makes a LOT more steps.)
Serge recently added a GitHub PR that patches the View export to allow choosing Tab delimiters. (Thanks again @SNoiraud !) Paul suggested in another thread that I patch the Import Text gramplet… but my ambition exceeds my Python skills. (I am clawing my way up from Python Novice a millimeter at a time.)