Merge two rows based on conditions using Power Query

Hi Anonymous ,
please check the enclosed file for the solution as well:

// Table1
let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type datetime}, {"Column2", type text}, {"Column3", type text}, {"Column4", type datetime}, {"Column5", type number}, {"Column6", type number}, {"Column7", type number}}),
    #"Added Index" = Table.AddIndexColumn(#"Changed Type", "Index", 0, 1, Int64.Type),
    #"Added Custom" = Table.AddColumn(#"Added Index", "EntryIndex", each if [Column5] = null and [Column6] = null then null else [Index]),
    #"Filled Up" = Table.FillUp(#"Added Custom",{"EntryIndex"}),
    #"Replaced Value1" = Table.ReplaceValue(#"Filled Up",null, each [Index],Replacer.ReplaceValue,{"EntryIndex"}),
    #"Filled Down" = Table.FillDown(#"Replaced Value1",{"Column1", "Column2"}),
    #"Grouped Rows" = Table.Group(#"Filled Down", {"EntryIndex"}, {{"Column1", each List.Min([Column1]), type nullable datetime}, {"Column2", each List.Min([Column2]), type nullable text}, {"Column5", each List.Sum([Column5]), type nullable number}, {"Column6", each List.Sum([Column6]), type nullable number}, {"Column3", each Text.Combine(_[Column3], " ")}}),
    #"Replaced Value" = Table.ReplaceValue(#"Grouped Rows",null,0,Replacer.ReplaceValue,{"Column5", "Column6"}),
    #"Inserted Addition" = Table.AddColumn(#"Replaced Value", "Value", each [Column6] - [Column5], type number),
    Custom1 = fnRunningTotal( #"Inserted Addition", "EntryIndex", "Value")
in
    Custom1