Do I need to fix remove the extra 20 rows from subscriber? (OR) remove table from replication and add re-initialize the single article? (OR) Shall I leave as it is.
That depends on what those 20 rows mean. Were they manually inserted on the Subscriber side intentionally? Or are they bad data / wrong to be in that table. The answer to that question will determine your course of action.
If the rows aren't hurting anything, replication is running fine, and we're inserted intentionally by someone, then leave them. If you don't know where they came from, and are bad data, then you can reinitialize to remove them, assuming your table's Article properties are set to DROP, TRUNCATE, or DELETE.
Note, you don't need to remove a table's Article from replication, in order to reinitialize it. But you can tell it to "Use a new Snapshot" when you reinitialize, if you want a clean slate essentially.