Update tables.md

Author: ksaha873

src/unify/profiles-sync/tables.md

@@ -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 in Profile events table, discussed above.
+     - A full **Profiles Backfill** to populate historical profiles data. Materialized views will have null `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**