Is there a keyboard shortcuts for switching tabs at Safari?
Select previous tab: ⌃⇧⇥ (control-shift-tab), ⇧⌘← (shift-command-left), or ⇧⌘[ (shift-command-[)
Select next tab: ⌃⇥ (control-tab), ⇧⌘→ (shift-command-right), or ⇧⌘] (shift-command-])

You can customize the shortcuts from System Preferences: