By default the tab titles will be derived from the statements. To override this you can use a comment with a tab= expression before the statement. For example:
-- tab=Department 10
select * from emp
where deptno = 10;
In this case the tab title is Department 10 instead of the default Select emp
There are also a few more that can be used, that are list in the Help section 7.10 Comment directives.