create or replace PROCEDURE proc (
  in_owner   IN         VARCHAR2,
  in_table   IN         VARCHAR2
) 
AS

...
...

TYPE tab_type IS TABLE OF in_owner.in_table%ROWTYPE;
tab_typ_finl tab_type;

TYPE ref_cur IS REF CURSOR;
plcur ref_cur;

...
...

Correct. You can't define dynamic types like this in PL/SQL. The name of the identifier must match the name of an underlying database object. You can't use a variable which holds the object name.

Presumably you're passing a table name and want a dynamic type because you're running dynamic SQL later in your code.

To suggest a meaningful workaround we'd need to understand why you're doing this. In the vast majority of cases static SQL is the Right Way to write your code. Dynamic SQL is harder to code. And opens up SQL injection risks.

So: why are you trying to this? What's the reason you can't use static SQL?