[notoverthere]

If you're interested in building it as a web app but want a keyboard-accessible grid / spreadsheet-like interface, then you have a few options.

The first resource I'd recommend is JSpreadsheets, which is a list of open-source JavaScript spreadsheet & data grid libraries. https://jspreadsheets.com

One of the most fully-featured JS libraries is Handsontable. It looks very flexible. They have some demos on their website to play with: https://handsontable.com/examples.html?headers

(Bonus: If you're using react, there's already a react component for using Handsontable: https://github.com/handsontable/react-handsontable )