Samsung Internet makes it easy to close your browser tabs thanks to intuitive controls, but this also means it's easy to accidentally close a tab. Fortunately, you can recover recently closed tabs on your Galaxy in just a few taps.
All you need to do go to the "Tabs" menu like you normally would, then hit the three-dot menu button in the upper-right corner and tap on "Reopen closed tab." As seen in the GIFs below, this button can reopen all the tabs you recently closed during the current browsing session. So if the tab you're after was closed a few tabs back, just keep tapping that menu button, then hitting "Reopen closed tab."
But know that the "Reopen closed tab" option disappears once you exit out of Samsung Internet for any reason, whenever your device goes to sleep, and when using "Secret mode." So, if you closed an interesting tab by accident, be sure to reopen it before getting out of the app.