By swinging his hammer in a circle, Thor can open up portals that allow him to traverse space and time, shown as how he travels from Earth to Asgard and vice versa, from Journey Into Mystery #103.
Thor's hammer transcends both space and time, from Thor #393.
Here, he sends the Masters of Evil through a space warp in Avengers #7.
Thor can also transport large objects. Here, he teleports an entire nuclear power plant away and its foundations to a dead world in Thor #393.
Thor can appear in the universe or entire dimensions WITHIN MOMENTS, from Fantastic Four #339.
and Thor #166.
Mjolnir's teleportive range is also virtually limitless. Here, he transports the possessed Warriors Three from the edge of the universe back to Asgard in Thor #185.
And if that's a little vague, the narration here specifically tells us Thor teleports millions of light years away, from Fantastic Four #338.
Mjolnir can also teleport between dimensions. Here, Thor sends innocent bystanders to Limbo to fight Durok the Demolisher alone in Thor #192.
While traveling at "a speed that is far greater than light," mjolnir creates a infinity vortex that teleports Kang the Conquerer and his time machine to a location outside time, from Thor #140.
Mjolnir could also transport several people to several different locations simultaneously, from Avengers #70.
Here he travels to Dormammu's Dark Dimension in Thor Annual #9.
Here, Mjolnir opens up a portal to the Negative Zone in Avengers #309.
Thor teleports the Destroyer Armor light years away(after Thor nearly gets killed by it), from Thor vol. 2 #2.