Using SET STATISTICS IO ON

I have a quick question regarding the use of the SET option SET STATISTICS IO ON.  When I use this to monitor the number of reads done by different queries I'll often see large numbers of reads on tables with names like '#7B053305.'  I understand Worktable tables shown in the output are for tables SQL creates on the fly to address sorts, group bys, order bys, etc.  What are these tables used for and how would I diminish large number of reads done on them?

Thanks.