Partitioning tables

Assume you are reading and writing regularly to a given table. 

1) When using Amazon RDS PostgreSQL 10, is there any reason to use table partitioning? 

2) If so what might be a few simple examples of when to use it? 

3) Also, if there is a reason then how large should a table be before it should be partitioned?  I am just wanting some general idea or scope. 

It is always a good idea to occasionally revaluate if going down a particular path still makes sense.

Thanks,

Lance