One of the most common practices and a wise recommendation is to display selected report parameter(s) in report … may be in header or body of SSRS report.
It’s a good reference when you export the SSRS report into available formats (Excel, PDF, Word etc.) Because if you don’t include/show selected parameter(s) in exported report then it becomes less-meaningful for a person who is reading/using the report … probably for some decision making.
So, how to fix it? Simple. Open that parameter’s properties dialog box. And fix the “Label field” as shown below.
And finally, you will see your parameter without un-wanted space … as shown below 🙂
I hope this will help you somewhere.