macro work but very slow

Try this

Option Explicit

Sub Equal()
    Dim c As Range
    Dim LR As Long, maxLR As Long, colNo As Long
    
    For colNo = Range("D:G").Column To Range("D:G").Column + Range("D:G").Columns.Count - 1
        LR = Cells(Rows.Count, colNo).End(xlUp).Row
        If LR > maxLR Then maxLR = LR
    Next
    LR = maxLR
    
    With Range("D2:G" & LR)
      .Value = Evaluate("IF(ROW(" & .Address & "),clean(trim(" & .Address & ")))")
    End With
    
    LR = Range("J" & Rows.Count).End(xlUp).Row
    For Each c In Range("J2:J" & LR)
       If c.Formula = True Then c.Value = c.Value
    Next c
    
    LR = Range("E" & Rows.Count).End(xlUp).Row
    Range("E2:E" & LR).Replace What:="-", Replacement:="", LookAt:=xlPart, _
            SearchOrder:=xlByRows, MatchCase:=False
            
    For colNo = Range("D:H").Column To Range("D:H").Column + Range("D:H").Columns.Count - 1
        LR = Cells(Rows.Count, colNo).End(xlUp).Row
        If LR > maxLR Then maxLR = LR
    Next
    LR = maxLR
    
    Range("D2:H" & LR).Replace What:=" ", Replacement:="", LookAt:=xlPart, _
            SearchOrder:=xlByRows, MatchCase:=False

End Sub

If this doesn't work

A sample workbook would help to clear up any guesswork

Cheers

EDIT:

Missing lines

LR = maxLR

Sorry for that.

Better if each section is written as a function.