You may have two preferences set that make it appear that Safari is malfunctioning.
If when you try to open a new Tab and Safari brings up a page showing your history, you most likely have one of your Preferences in Safari set to "Open new pages with "History" (you can choose any number of things here).
If you are opening new Tabs by clicking the "New Tab" button, it will invoke this Preference. Same goes for File : New Tab from the Menu Bar. I always open new Tabs by simply holding down the Apple (Command) Key when clicking on a link or bookmark. This opens whatever you just clicked on in a new Tab (saving you the hassle of more steps!)
Good Luck! Beware, however, that if you are opening a bookmark from the Bookmarks Bar and it exists in a Folder there, you must NOT hold down the Apple key while clicking on the Folder itself, but only when you're ready to click on the bookmark link you're seeking. Otherwise, holding down the Apple Key while clicking on the Bookmark Folder will open _each and every single bookmark within the Folder in a new Tab, all at once (what a pain!).
Happy clicking 😛
