I don't know of any way to insert newlines into aliases in Tableau. A possible workaround is to create a calculated field in Tableau that could looks something like this:
WHEN "Office Supplies" THEN "Office
WHEN "Technology" THEN "Technology"
WHEN "Furniture" THEN "Furniture"
Also, you could create a mapping for the aliases in your datasource and Tableau will respect that, see the attached for a couple of examples.
new line.twbx.zip 1.1 MB
Perfect, did the trick. Thanks for the assistance - Briann