Bulk Excel Data Management Cleanup

I have a spreadsheet holding well over 100,000 mixed-type records—text fields, numeric columns, a few calculated cells—and it needs to be brought to a usable state. Right now the file is a single Excel workbook; no separate databases or flat files are involved.

Two things must happen:

• Data entry – several columns are still blank or contain placeholder codes that need to be filled from a secondary sheet I will supply.
• Data cleaning – duplicates removed, inconsistent text normalised, numeric outliers flagged, and all formulas verified so totals match source balances.

The finished workbook should open quickly, pass a spot-check for accuracy, and be free of hidden errors (broken links, stray formats, unused styles). Feel free to use Power Query, VBA, or any other Excel-friendly approach as long as the final deliverable remains a standard .xlsx file with clear documentation notes on any automated steps you add.