I've logged an enhancement for next version to be able to make your SQL file like this, and Toad will name the sheets if you specify them. I'll post back here when this is available.
-- sheetname: small_emp_no
select * from EMP where empno < 7500;
-– sheetname: large_emp_no
select * from EMP where empno > 7500;
-– sheetname: DEPT
select * from DEPT;
select * from BONUS;
Update 12/9/2019: This has been added in Toad for Oracle 13.3 Beta
You can also specify filename or table name with comments (for exporting to other formats)
-- filename: my_awesome_file
-- tablename: my_awesome_table
-- schemaname: my_awesome_schema