Because of the size, your paperweight is a special Italian beauty, made in Murano (Venice) by either Fratelli Toso - literally Toso Brothers or Moretti And Fratelli (or Moretti Brothers). But it is Murano. I saw a number of these oversize paperweights, some of them 6, 7, or 8 inches wide overall and about 6, 7, 8 or inches high, all Muranese while in Venice in October. They were selling for between 150 and 250 Euros. Every single one that I saw was filled with the millefiori cane work, some similar to the millefiori cane work in your item.
As noted in other posting, large, oversize paperweights are generally called doorstop weights because some people actually used them to hold open doors.