If the vector does not change (you just want to copy some static data from one file to another), copy/paste will work, but with a couple twists. Select the data in the table, right click, then "Copy Selection" (not copy). Then go to the new worksheet Menu Insert > Data > Table to create a table. Then right click and "Paste Table".
Or if the data will change, the other way is to save it as a file, then read it in from the other mathcad worksheet. Go to Menu Insert > Data > File Input or File Output. You can save and read in a variety of formats.
Peter