Close file before moving onto the next file - vba

Question

This macro loops through all the files in a directory and formats the data as a table.
I need to sort Column J on the table from Largest to Smallest and then save the file before moving onto the next file. Currently it leaves all the files open.
Sub LoopThroughFiles()
FolderName = "C:\Folder1\"
If Right(FolderName, 1) <> Application.PathSeparator Then FolderName = FolderName & Application.PathSeparator
Fname = Dir(FolderName & "*.xls")
'loop through the files
Do While Len(Fname)
With Workbooks.Open(FolderName & Fname)
Dim tbl As ListObject
Dim rng As Range
Set rng = Range(Range("A1"), Range("A1").SpecialCells(xlLastCell))
Set tbl = ActiveSheet.ListObjects.Add(xlSrcRange, rng, , xlYes)
tbl.TableStyle = "TableStyleMedium2"
Columns("A:L").Select
Columns("A:L").EntireColumn.AutoFit
End With
'go to the next file in the folder
Fname = Dir
Loop
End Sub

Answer 1

You are missing the line where you Close the workbook : WB.Close True.
(if you don't want to save the changes made to the workbook use WB.Close False)
Note: you are not setting the Worksheet object on the workbook you open, so by default it will assume the ActiveSheet, which is the last ActiveSheet the last time you saved this workbook.
Try the code below:
Sub LoopThroughFiles()
Dim WB As Workbook
FolderName = "C:\Folder1\"
If Right(FolderName, 1) <> Application.PathSeparator Then FolderName = FolderName & Application.PathSeparator
fname = Dir(FolderName & "*.xls")
Application.ScreenUpdating = False
Application.DisplayAlerts = False
'loop through the files
Do While Len(fname)
Set WB = Workbooks.Open(FolderName & fname) '<-- set the workbook object
With WB
Dim tbl As ListObject
Dim rng As Range
Set rng = Range(Range("A1"), Range("A1").SpecialCells(xlLastCell))
Set tbl = ActiveSheet.ListObjects.Add(xlSrcRange, rng, , xlYes)
tbl.TableStyle = "TableStyleMedium2"
Columns("A:L").Select
Columns("A:L").EntireColumn.AutoFit
End With
WB.Close True ' <-- close workbook and save changes
' go to the next file in the folder
fname = Dir
Loop
Application.ScreenUpdating = True
Application.DisplayAlerts = True
End Sub