I have created a table and now i want to insert some 500 rows in it using a single insert command.
Please let me know the script using a for loop.
It is highly important to have knowledge of source of the records.
If you are having the records in an excel file/csv file, then you may opt for External Tables/SQL Loader.
If the source of Data is a Table on Remote data base, you can use INSERT INTO your_table SELECT FROM REMOTE_TABLE. Or if the Insert and Select is a periodic activity, you may want to consider the use of Materialized Views.
Most performant way of performing a Job is to achieve it via SQL rather than relying on PL/SQL. As SQL shall almost always outperform PL/SQL.
Now, if you can provide us some data and the table structures that match your scenario, it will be helpful for you as well as us to provide some suggestions that shall be beneficial for you.