The short answer would be "lots". I'll cite examples from the three books I currently have sitting on my desk, "World Mythology" by Donna Rosenberg, "Bulfinch's Mythology" by Thomas Bulfinch, and "Mythology in the Middle Ages: Heroic Tales of Monsters, Magic, and Might" by Christopher Fee, though there are many, many named weapons (I really hope others can expand on this, especially Hindu and Shinto, though I can't speak with enough confidence on them).

So you mentioned Excalibur, or Caliburn, but Arthur also had a dagger named Carnwennan which could ostensibly cloak its wielder in shadow, and a spear named Rhongomyniad, though sources are split on the significance of this weapon since the name essentially translates to "striking spear" (or basically just a spear) and the significance of whether the weapon makes the legend or the legend makes the weapon is more of a philosophical one.

The Ulster Cycle of Irish folklore mentions a few weapons. Some of the more notable ones are the Gae Bolg, a spear wielded by Cúchulainn along with his sword Fragarach, and the Caladbolg, a sword wielded by Fergus mac Róich - both of which were said to be able to sunder hills in twain.

There is of course the Norse mythology, the most famous being Thor's hammer Mjolnir. Odin's spear was named Gugnir. Loki wielded a sword or wand known as Lævateinn or "damage twig". Gram, also known as Nothung, was wielded by Sigurd. The sword Tyrfing, a cursed blade, also had multiple owners throughout the Poetic Edda.

Beowulf wielded two swords, one that he owned and one borrowed, Naegling and Hrunting respectively.

Or if you're more into historical examples then next time you're in Paris you can check out Joyeuse, the sword of Charlemagne.

El Cid was known to carry two swords: Tizona and Colada.

(I'm playing a bit fast and loose with the time frame of pre-Arthurian but hopefully the information is still relevant)

More of course can be said here, but this old thread has a response which might interst you from /u/RockNRollJedi.