Solution 1:

First off, the high number is the average energy impact, not the current.
This is in line with what you say you currently have open: merely 4 tabs.

Since I don't know what you have been doing before, I can't tell you exactly what might have caused this energy impact. But there is quite some cached Safari web content (Safari is using too much RAM. How can I reduce its memory footprint?, quite old though).

Probably the easiest way to solve the issue is to (force) quit Safari (Activity Monitor → Safari → in the left upper corner X → Quit/Force Quit) and restart your MacBook Pro.

If the problem persists try to delete web page cache with Safari → Preferences → Privacy → Advanced → Show Develop menu in menu bar, then in the menu bar at the top Develop -> Empty Caches.

You can also follow this guide, it also explains how to delete cookies:

  • https://www.macworld.co.uk/how-to/mac-software/clear-safari-cache-3496193/

Note: Flash Player is a notoriously bad extension (slow and unsecure). If you have it installed, remove it. You shouldn't need it these days. You can read more about it here:

  • https://lifehacker.com/you-really-shouldnt-be-running-adobe-flash-player-anymo-1829721122