Anytime I see something that looks like Excel on the web, I cringe.
Unless you are Microsoft or Google and you are putting spreadsheets on a website (SoW), you are almost certainly doing something wrong.
---
Case 1: A co-worker (or yourself) previously wrote an excel-based app and now it's time to put it on the web for wider distribution. You implement the app with a custom gridview/spreadsheet.
Error in Case 1: The UI was copied, but what is almost always needed is an input wizard with validations and workflow along with a reporting backend.
---
Case 2: You have a database that you need to share in a human readable format.
Error in Case 2: Implement export functionality instead, you will never be able to implement all the features of Excel, and at some point someone will need that feature.
---
Case 3: You have a very small and well defined case that actually calls for SoW!
Error in Case 3: Your very small SoW app will grow and grow and strangle you.
---
Case 4: You want to challenge the stranglehold of Google Sheets and MS Office 365.
Error in Case 4: There is no error here, only madness.