Problems with slow code, can this be coded differently to speed it up.

Hi

I have a small project that i am developing and its coming along OK. The problem I have is the clunky code I think, it takes to long to populate, its not too bad on my i7 processor but when I move it to my tablet its not quick enough.

I will explain the purpose of the application.

I have a sheet that holds all the data called "MatsData" and a userform called "frmcontract"

There are two listboxes "Listbox1" & "Listbox2" The category name from cell "C" in "MatsData" populates into the "Listbox1" whichever category that is chosen in "Listbox1" is transferred to "Listbox2". When you have completed choosing the categories you hit the + button to create the document; this is where it slows up, I know the code looks complex and it does for me. I had this code written by a friend and he is unavailable to help, I cannot work it out due to my limitations I am relatively new to vba and only pick things up from you good guys, I would appreciate if someone could shed some light on this. I have attached the file.

Thanks