Most People Should Wait for the OTA
The Galaxy Tab Android Pie update is moving slowly and it'll take months to complete. Some updates probably won't arrive until the fall.
If you're feeling impatient and don't want to wait for the update, you can manually install the software right now if you have the right device, a little bit of patience, and some free time.
The official Galaxy Tab S4 firmware is out which means those users can skip the OTA (Over-the-Air) roll out and manually install the software right now.
If you're dying to install Android Pie, you might be tempted to go this route. However, you should only go through with this process if you feel comfortable with it.
If you feel uncomfortable with any part of the manual installation process you'll want to hang back and wait for the OTA.
Manually installing the software can cause unforeseen issues (it's possible to brick your tablet) so make sure you're one hundred percent confident. If you aren't sit back, relax, and wait for the OTA.