Is there’s a database tables documentation to clearify each table’s function like concept_reference_term, concept_reference_map, etc…
Thank you
Have you tried to google?
You can take a look at the javadocs on the corresponding classes, there is a naming convention followed that allows one to infer the mapped java class to a given table e.g. concept_reference_term and concept_reference_map map to ConceptReferenceTerm and ConceptReferenceMap respectively.
There are various pages on the openmrs wiki which try to explain concept tables with some practical examples. This might help:
https://wiki.openmrs.org/display/docs/Concept+Data+Model
Feel free to improve.