Update tables.md

Author: ksaha873

src/unify/profiles-sync/tables.md

@@ -107,7 +107,7 @@ With raw tables, you have full control over the materialization of Profiles in y
 
 Raw tables contain complete historical data when using historical backfill. 
 
-Note: `Timestamp` column will be empty for backfilled data. This is because reverse engineer historical profile changes from the current state of the profile.
+Note: `Timestamp` column will be empty for backfilled data. This is because reverse engineer historical profile changes from the current state of the profile, and do not have access to the actual event timestamps.
 
 ### The id_graph_updates table
 
@@ -298,7 +298,7 @@ If you're not using materialized views for Profile Sync and would like to switch
 2. **Request a Full Profiles and Events Backfill**
    - After enabling the materialized views, you'll need to ensure historical data is populated in the materialized tables.
    - Write to [[email protected]](mailto:[email protected]) and request:
-     - A full **Profiles Backfill** to populate historical profiles data. Materialized views will have nil `Timestamp` for the same reason as Profile events table, discussed above.
+     - A full **Profiles Backfill** to populate historical profiles data. Materialized views will have nil `Timestamp` for the same reason as in Profile events table, discussed above.
      - An **Events Backfill** to include any relevant historical events, including a date range for Segment to pull data in for the events backfill. 
 
 3. **Verify Your Data**