i second WillyB & jaswinder-s
"open note in new tab" (via contextmenu or menu->note) should do what it says: open a new tab and show only the note within this tab (without any nonse on the left like "all notes", "notebooks", "shared with me", "tags", "work chat"; via menu->view) — otherwise tabs get completely useless as the tabs title does not reflect the node it currently shows
you can think of this as "open note in new window" (which actually opens a new window and only shows the note within, without any nonsense on the left) and then moving thios window into another as a tab --> a behaviour any and every web browser i know of offers
plz evernote get your sh*t together, thanx