Hi Natalie,
it seems that your wiki tables haven't been deleted (dropped) properly when you have deleted the module from "Admin/Modules" and then, the re-install of the module is crashing because tables are there yet.
I think you should go to DB and drop all the "wiki" tables (and only those!!). Then, re-installation should work fine.
Ciao
Wiki
whoops...
اس بحث کو بند کر دیا گیا ہے لہذا آپ اس کا مزید جواب نہیں دے سکتے۔