Hi there carmelles,
Thanks for joining us in Apple Support Communities! We understand you're seeing tabs from your iPhone in Safari on your Mac, and you're asking how to turn that feature off. We're glad you're here, and we can provide some guidance.
To begin, it sounds like you're using iCloud Tabs on your devices. "iCloud keeps the tabs you have open in Safari up to date on your iPhone, iPad, iPod touch, and Mac. That means you can go from one device to the next and pick up browsing wherever you left off." Have a look at this support article to learn how to turn off iCloud tabs on your Mac and iPad:
Set up and use iCloud Tabs
Next, the links below provide details about clearing your browsing history on both devices:
Clear your browsing history in Safari on Mac
Clear the history and cookies from Safari on your iPhone, iPad, or iPod touch
Also, you could use Private Browsing. "When you use Private Browsing windows, the details of your browsing aren’t saved, and the websites you visit aren’t shared with your other devices." These resources provide more information about how Private Browsing in Safari works:
Use Private Browsing in Safari on Mac
Turn Private Browsing on or off on your iPad
We hope this information is helpful. Don’t hesitate to let us know if you have any more questions.
Cheers.