To center a paragraph is separate from adding tabs, yes. You can use the Ctrl+E shortcut to apply center formatting.

The best way to delete "excessive" spacing depends on how it was added in the first place. If you pressed Enter you can backspace to delete the paragraph marks thus inserted. To get a better view of what is going on, display nonprinting marks for example by pressing the ¶ button (not sure where you'll find it in MacWord though).

With nonprinting marks displayed, paragraph marks show as ¶ symbols.

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Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional