Vaadin

If you already know Java, then the obvious choice is the Vaadin Framework.

Vaadin lets you rapidly develop a web app user-interface using only pure Java. Your app lives on the server-side, where you specify fields, labels, buttons, data grids, and other widgets arranged in layouts using only Java code.

At runtime, Vaadin generates the necessary HTML, CSS, DOM, and JavaScript to render remotely in the user’s web browser. As the user types in fields, clicks buttons, and so on, your server-side Java code is automatically invoked to respond.

So you can build professional-looking business apps that run quickly, reliably, and securely without having to learn that alphabet-soup of web technologies: HTML, CSS, DOM, JavaScript, AJAX, WebSocket, Push, etc. Vaadin uses all those standard web technologies, but does do on your behalf, behind the scene.

Vaadin is free-of-cost and open-source. In addition, the company Vaadin Ltd does sell a spreadsheet add-on if you need it. But the built-in powerful and flexible Grid widget may suffice from what I can seen in that screenshot you posted.

For a database, you might want to use the H2 Database Engine. It is built in pure Java, and is free-of-cost, open-source, and actively developed. But if you need heavy-duty enterprise-level reliability, then Postgres.