Thank you horseyride. i was able to make your solution work.

As i continued googling, I also came across the "earlier" DAX function, which allows me to add a column easily. It is not done in the import like I asked, but does what i wanted by keeping the amount of data imported to the original single table set.

EARLIER(, )

the formula I used is this:

NextOrderDate = 
  CALCULATE(
      MIN(Orders[OrderDate]),
      FILTER(
          Orders,
          Orders[Item] = EARLIER(Orders[Item]) && 
          Orders[OrderDate] > EARLIER(Orders[OrderDate])
      )
   )