If you had field with constrain or validation on your table, then you want to add row on that table, your new row would not save directly. Instead, there would be a highlight and a sign on the row that says your data should meet the validation before it saved to the database.
Example:
Delete Row
Steps to delete row on your table:
Hover on row you desire to delete, click on triple dot icon
Click "Delete this row" option
Warning: You can't undo deleted row or retrieve your deleted data. So before you delete your row, make sure you didn't use the data.