Is there something I'm doing wrong? How can I view my postgreSQL tables from a SQL Developer connection?
Please do a Google Search for "sql developer postgresql"
The very first post is a Stack Overflow question on this very same topic. I didn't read it. There seem to be other potentially informative results.
You are more likely to find a SQL Developer that happens to use PostgreSQL (as well) as opposed to a PostgreSQL person who happens to use SQL Developer. IOW, other forums are more likely to yield fruit.