When you say "in one line", I suspect you are not just talking about using a vertical bar character
| instead of a newline. Rather, I suspect you are looking for a shorter way of performing your task.
You can get what you want by combining the existing suggestions into a user-defined command (see
help :command). User-defined commands must start with a capital letter.
For example, if you are a C++ programmer, it may be that you like to open a new tab that has the implementation and header files side-by-side. At that point you can define a command such as this in your
:command -nargs=1 -complete=file Tabv tabe <args>H | vs <args>C
Which can be used thus:
Foo.C on the left and
Foo.H on the right in a new tab.
If your typical usecase is not this specific, it may be more difficult to save keystrokes. Since you are asking this on SU instead of SO, perhaps you are not a programmer, but hopefully you can adapt this suggestion to fit your needs.