The browser and your default copy paste will not allow selective paste and separation into all those text box fields. Why?
At best you can copy-paste between the two, but for "data cell separation" you will need logic that does the following:
- Assuming, that it can receive paste information/ data from Spreadsheet/ Clipboard, it needs to do so first
- Parse through that data
- Logically Map Structure of incoming data to text-box fields in browser
That is a lot of 'custom logic' that will have to be built to "run inside the browser".
From a solutions point of view, your best way to do this would probably be Browser extensions & plugins (Chrome & Firefox have brilliant) & Scripts that can run in engines such as GreaseMonkey/ TamperMonkey.
Someone, will have to code/ script that; learn yourself or find someone good with the above.
Even then the critical juncture would be the boundary where the Browser & its components begin to receive the data, and if so how, from the OS+Spreadsheet environment, as they are kind of walled sandboxes to each other.
For ideas, inspiration & seeing the capability limitations, I'd suggest looking at Chrome/ Firefox extensions & plugins that do a lot of "Auto-Fill" and automation in the Browsers.
I use LastPass, Evernote a lot as well as several GreaseMonkey scripts.