Try this in powerquery
let Source = Excel.Workbook(File.Contents("C:\temp\a.xlsx"), null, true),
start=List.PositionOf(Source[Name],"TTP"),
TabsToKeep=List.Range(Source[Name],start+1,List.PositionOf(Source[Name],"TTL")-start-1),
Filtered= Table.SelectRows(Source, each List.Contains(TabsToKeep, [Name])),
List = List.Union(List.Transform(Filtered[Data], each Table.ColumnNames(_))),
#"Expanded Data" = Table.ExpandTableColumn(Filtered, "Data", List,List)
in #"Expanded Data"
then right click and remove extra columns
EDIT
For multiple files, steps spread out for easy follow
let Source = Folder.Files("C:\temp3"),
#"Filtered Rows" = Table.SelectRows(Source, each ([Extension] = ".xlsx")),
#"Removed Other Columns" = Table.SelectColumns(#"Filtered Rows",{"Name", "Content"}),
#"Added Custom" = Table.AddColumn(#"Removed Other Columns", "GetFileData", each Excel.Workbook([Content],true)),
#"Added Custom1" = Table.AddColumn(#"Added Custom", "Custom", each List.PositionOf([GetFileData][Item],"TTP")),
#"Added Custom2" = Table.AddColumn(#"Added Custom1", "Custom.1", each List.PositionOf([GetFileData][Item],"TTL")),
#"Added Custom3" = Table.AddColumn(#"Added Custom2", "Custom.2", each List.Range([GetFileData][Item],[Custom]+1,[Custom.1]-[Custom]-1)),
#"Added Custom4" = Table.AddColumn(#"Added Custom3", "Custom.3", each let find = [Custom.2] in Table.SelectRows([GetFileData], each List.Contains(find, [Item]))),
#"Expanded GetFileData" = Table.ExpandTableColumn(#"Added Custom4", "Custom.3", {"Data", "Hidden", "Item", "Kind", "Name"}, {"Data", "Hidden", "Item", "Kind", "Sheet"}),
#"Removed Columns" = Table.RemoveColumns(#"Expanded GetFileData",{"Content", "Hidden", "Item", "Kind", "GetFileData", "Custom", "Custom.1", "Custom.2"}),
List = List.Union(List.Transform(#"Removed Columns"[Data], each Table.ColumnNames(_))),
#"Expanded Data" = Table.ExpandTableColumn(#"Removed Columns", "Data", List,List)
in #"Expanded Data"