The Samsung Galaxy Tab 3 7.0 (SM-T211), originally released in 2013, is a classic dual-core tablet that shipped with Android 4.1 Jelly Bean and officially peaked at Android 4.4 KitKat. Today, trying to run modern apps on Android 4.4 is nearly impossible due to dropped API support, security vulnerabilities, and heavy TouchWiz bloatware.
Developers managed to port unofficial builds of CyanogenMod (the predecessor to LineageOS) to the PXA986 platform.
If you want to move forward with updating your tablet, let me know: