I think you are looking for
:tabe +set\ nomodifiable|set\ ro filename
+ after tabe lets you specify a set of commands to run when opening the file. For more details, see
If this is something you do often, you can set up a custom command to do this for you
:command! -nargs=+ -complete=file Tabread tabe +set\ nomodifiable|set\ ro <args>
Place that in your .vimrc to have it whenever you start vim.
This command will create a new user command called
Tabread that supports filename completion (so you can use it like
tabe). It sets those options for you and opens the file in a new tab.
nomodifiable option prevents editing commands from working on the buffer, and the
ro option prefents writing the buffer to disk.