I'm using Toad 9.5 and is not able to insert or update data in a table in a schema name "REMARK" in the Schema Browser | Table | Data Grid. I used to be able to do this in Toad 9.0 where I just needed to select the cell and enter the changes or insert new data, then click on the commit icon.
Then name "REMARK" is an Oracle Reserved Word in 10g database. Therefore, it and any other Reserved Words should not be use to name schema or other database objects. The feature still works in Toad 9.0 because this version of Toad did not support 10g yet.
It is not recommended to use Oracle Reserved Words such as "REMARK" to name database objects, instead please try one of the suggestions below:
1. Choose a different word
2. Use "REMARKS" with an "S".