A database is only as good as the information it contains. It's important to edit the information in your database to keep it accurate and up to date. You can update and modify spatial (features on a map) and nonspatial data (a stand-alone table of sales figures, for example) through the Table view.
ArcGIS AllSource automatically starts an edit session when you modify existing data or create new data. There are no buttons to start or stop an edit session. When you make edits in the table view, the edit session remains active until you save or discard your edits. If you want to safeguard against unintentional edits, you can customize the Edit ribbon to include the hidden Enable editing button 
, which prevents editing unless it has been purposefully enabled.
Some tables are not editable, such as text files (.xls, .xlsx, .txt, and .csv, for example). These tables are read-only. If you edit this data externally, you must add the text file to the project again. However, Microsoft Excel workbook files can be refreshed in ArcGIS AllSource to reflect updated data and schema edits made to any of the worksheets in the workbook.
Some attributes are not editable in the table. All managed fields, such as ObjectID, Shape_Length, and Shape_Area, are not editable. You are also restricted from editing fields that have been demarcated as read-only for the layer in the Fields view of the table. You can edit joined tables but only the base table fields. Fields from the joined table are read-only.
Edits can include editing a value in a table cell and editing a field with contingent values. You can also copy and paste values from applications external to ArcGIS AllSource, as described in the following section.
Copy and paste values from other applications
To update an existing database table with information from another application, such as Microsoft Office Excel or Word tables, you can paste a single cell value, values for an entire row, or values of consecutive columns.
Copy the information from the other application that you need to the clipboard. Highlight the starting cell in your database table inside ArcGIS AllSource and paste the values using Ctrl+V or right-click and click Paste. New rows are created if the number of pasted values for a field
is greater than the current table row count. Pasted values are also rounded to match the numeric format of the
field. For example, pasting 2.7 into an integer field rounds
the value to 3.
Commit your edits to the database by clicking Save Edits 
in the Manage Edits group, which for tables opened from a map is found on the Edit tab and for tables opened from the Catalog pane or Catalog view is found on the Table tab.
If a pasted item is invalid for the field you are editing, a warning appears. For example, this occurs when pasting a value outside of a range domain or pasting a text value into a numeric field. The cells are not modified.
The following tips may be helpful when copying and pasting values:
- Table filtering is honored. If your table has a definition query or hidden fields, the pasted values do not modify the data outside the current filter.
- Pasting empty values into a field that allows null values pastes a null value.
- You can use either the code or description to paste into fields with subtypes or domains.
Copy and paste from another ArcGIS AllSource table
You can add data to an existing table by pasting values copied from another table in the same or another ArcGIS AllSource project. Copy and paste is a recommended workflow to update and replace existing values with new information. If more rows are pasted than currently exist in the database table's row count, additional rows are automatically created. However, if more columns are pasted than currently exist, additional columns are dropped.
Insert new rows into a stand-alone table
You can insert new rows into an active stand-alone table. Click the Insert Rows button 
and provide the Number of rows value to add to the table. Click Create or press Enter.
Note:
- You can add a maximum of 1,000 rows at one time.
- If a definition query is being used, the new rows may not appear.
Duplicate a row in a table
You can create a duplicate copy of the attributes of a feature or record. Right-click the row header and click Duplicate Row 
to create a copy of the chosen row at the bottom of the table. It is selected. The geometry of a feature is included when duplicating a row.