For the Duplicate rows to be enable in the Editor window, please be sure that the data grid is in editable mode. The data grid that displays the results of the SQL queries is fully editable providing that the query itself returns an updatable resultset. Query statements MUST return the ROWID to be updatable.
"select * from employee", would not be updatable
"select employee.*, rowid from employee", would be updatable.
To reduce required keystrokes, you can substitute EDIT for SELECT * FROM and Toad will translate into the updatable version of the statement.
"edit employee", will return the same result as select employee.*, rowid from employee.
If the resultset should be editable but remains read only, make sure the Toad Options | Data Grids | Data tab, Use Read-Only Queries check box is NOT enabled.
For the Generate Insert Scripts for Selected Records, please try the steps below:
1. Right click and select Row-Select for the data grid.
2. Hold Ctrl Key + each of the record rows you want to select | Right-Click one of the rows selected | choose "Export Dataset".
3. In the Export Data window | choose "Insert Statements" under "Export Format:" | then check the check box for "Export only selected rows".
Choose the type of output you want under the "Output" section and click OK.