
Samsung Galaxy Tab4 8.0
The latest firmware for Samsung Galaxy Tab4 8.0 (SM-T330NU) is T330NUUES1BPL1 with Android 5.1.1 (Lollipop), released on December 18, 2016 for 2 regions (CSC). Every official firmware build for SM-T330NU, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/T330NUUES1BPL1
SM-T330NU started on Android 4 and has received 1 major Android upgrade; it now runs Android 5.1.1 (Lollipop). The newest build, T330NUUES1BPL1, was released on December 18, 2016. No new build has appeared for 119 months, so regular updates for this model have most likely ended.
Specifications of SM-T330N, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-T330X

SM-T337V

SM-T332

SM-T230X

SM-T320X
The newest firmware for SM-T330NU runs Android 5.1.1 (Lollipop): build T330NUUES1BPL1, released on December 18, 2016.
The latest build for SM-T330NU, T330NUUES1BPL1, was released on December 18, 2016 (9 years ago).
SM-T330NU has had no new firmware for 119 months, so regular updates have most likely ended.
Yes, all firmware files for SM-T330NU are 100% official, original, and obtained directly from Samsung servers.
To flash SM-T330NU, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-T330NU.