When you open an article with double-click, or with Open for editing / Open for viewing options of the right-click menu, and there are other articles already open, the new article is displayed in the additional tab as on the following screenshot. In that way, you can switch quickly to another article.

An alternative is to use Add Tiled Vertically or Add Tiled Horizontally options of the right-click menu: in that case, articles are opened as tiled, so you can review them at once.

If you already have some articles opened in additional tabs as on the first screenshot, you can tile them easily, by a right-click on a tab, and selecting Tile Vertically or Tile Horizontally (one-by-one).