Reusing tab styles

Tabs don't define a fixed space, they define a fixed postion on the line.  I suspect what you may really want is to use some combination of fixed width spaces (em space, en space, etc.) between words.

Create a new style and then use the Based On section and select your original style with the tab options.

Then when you change the original style it will change in all the styles that have Based On selected.

https://helpx.adobe.com/ie/indesign/using/paragraph-character-styles.html