Hi Nicholas,

You will want to build a Change Detection workspace. Safe software recently held a two part webinar on this topic.

 https://docs.safe.com/fme/html/FME-Form-Documentation/FME-Transformers/Transformers/changedetector.htm You want the existing TAB going into Original port and the new data into the Revied input port. Coming out of the transformer are Insert, Update, Delete ports and a format attribute called fme_db_operation which you use in the writer table operations instead of simply Insert or Update. 

I figured it out
The trick is to use the Precisely MapInfo Extended TAB Writer and take advantage of the Feature Operation

To Insert new rows

Reader

This is a simple MapInfo (MITAB) Reader. It's job is to Read the new rows that are to be inserted

Writer

This is a Precisely MapInfo Extended TAB Writer
The Table Name is the name of the "master" table

The Feature Operation is Insert

Note that the Feature Operation uses the Existing table
This will Insert the Input features 
The table is saved at the end. 

To Delete existing Rows

Reader

This is a simple MapInfo (MITAB) Reader. It's job is to Read the rows that are to be deleted. There must be a column with an identifying unique value.

Writer

This is a Precisely MapInfo Extended TAB Writer
The table name is the name of the "master" table

The Feature Operation is Delete

Note that the feature operation uses the Existing table and also performs a Pack
The table is saved at the end

The Row Selection is by Matching a Column

In this case, any row with a value in the districtcode column that matches the Input features will be deleted.

(I did have a bunch of screenshots, but they make my post too large for the forum)