let
Source = Excel.CurrentWorkbook(){[Name="Table2"]}[Content],
GroupByProject = Table.Group(Source, {"Projects"}, {{"All", each _, type table [Projects=text, Customers=text]}}),
GetList = Table.AddColumn(GroupByProject, "List", each Table.Column([All],"Customers")),
ExtractList = Table.TransformColumns(GetList, {"List", each Text.Combine(List.Transform(_, Text.From), ","), type text}),
DeleteCol_All = Table.RemoveColumns(ExtractList,{"All"})
in
DeleteCol_All