How can I open Sublime Text 2 files from the command line in linux to a tab, not a new window

Try Sublime command line help

subl –help
Sublime Text 2 Build 2217

Usage: subl [arguments] [files]         edit the given files
   or: subl [arguments] [directories]   open the given directories
   or: subl [arguments] -               edit stdin

Arguments:
  --project <project>: Load the given project
  --command <command>: Run the given command
  -n or --new-window:  Open a new window
  -a or --add:         Add folders to the current window
  -w or --wait:        Wait for the files to be closed before returning
  -b or --background:  Don't activate the application
  -s or --stay:        Keep the application activated after closing the file
  -h or --help:        Show help (this message) and exit
  -v or --version:     Show version and exit

--wait is implied if reading from stdin. Use --stay to not switch back
to the terminal when a file is closed (only relevant if waiting for a file).

Filenames may be given a :line or :line:column suffix to open at a specific
location.

After you have opened a new window the subsequent files should be added there as per the default behavior.