The names aren't the same. That was the point that I was trying to make.

Run the following to understand what I am trying to explain:

    create table tab1( id number(10) );

    create table "Tab1"( id number(10) );

    create table "tab1"( id number(10) );

    select * from USER_CATALOG where UPPER(SUBSTR(TABLE_NAME,1,3))='TAB'

You won't get an error creating the tables and you will see the three tables in your catalog.