mouse mat
Computers
ˈmouse mat (also mouse pad American English) noun [countableC] 
a small piece of flat material with a special surface which you move a computer mouse on 鼠标垫 →4 See picture on 见图 Page A8 In the office 办公室里 →5 see picture at 见图 officeExamples from the Corpus
mouse mat• Furthermore, the pen is more compact and requires no mouse mat.
From Longman Business Dictionary
mouse matˈmouse mat British EnglishBrE, mouse pad American EnglishAmE noun [countableC]COMPUTING
the thing on which you place a computer’s mouse, and which allows you to move it easily