Load multiple tables in Power Query with loop

BBL 
You can use the concept of "Invoking Custom Functions" to achieve this.

I tried using Excel files and it works fine. You can use the similar approach with your database.

Create custom function as -

(YearMonth as text) =>
let
Source = Excel.Workbook(File.Contents("C:\Users\VMakhij\" & YearMonth & ".xlsx"), null, true),
Sheet1_Sheet = Source{[Item="Sheet1",Kind="Sheet"]}[Data],
#"Promoted Headers" = Table.PromoteHeaders(Sheet1_Sheet, [PromoteAllScalars=true]),
#"Changed Type" = Table.TransformColumnTypes(#"Promoted Headers",{{"Category", type text}, {"YearMonth", Int64.Type}, {"Sales", Int64.Type}})
in
#"Changed Type"

Next, create your table which will be using the above function -

let
StartDate= #date(2018,01,01), 
EndDate = DateTime.LocalNow(), 
DateList = List.Dates(StartDate, Number.From(EndDate)- Number.From(StartDate)+1 ,#duration(1,0,0,0)),
#"Sorted Items" = List.Sort(DateList,Order.Ascending),
#"Converted to Table" = Table.FromList(#"Sorted Items", Splitter.SplitByNothing(), null, null, ExtraValues.Error),
#"Changed Type" = Table.TransformColumnTypes(#"Converted to Table",{{"Column1", type date}}),
#"Renamed Columns" = Table.RenameColumns(#"Changed Type",{{"Column1", "Date"}}),
#"Added Custom" = Table.AddColumn(#"Renamed Columns", "YearMonth", each Number.ToText(Date.Year([Date])) &
Text.PadStart(Number.ToText(Date.Month([Date])),2,"0")),
#"Changed Type1" = Table.TransformColumnTypes(#"Added Custom",{{"YearMonth", Int64.Type}}),
#"Removed Columns" = Table.RemoveColumns(#"Changed Type1",{"Date"}),
#"Removed Duplicates" = Table.Distinct(#"Removed Columns"),
YearMonth = #"Removed Duplicates"[YearMonth],
#"Sorted Items1" = List.Sort(YearMonth,Order.Descending),
#"Converted to Table1" = Table.FromList(#"Sorted Items1", Splitter.SplitByNothing(), null, null, ExtraValues.Error),
#"Renamed Columns1" = Table.RenameColumns(#"Converted to Table1",{{"Column1", "YearMonth"}}),
#"Added Index" = Table.AddIndexColumn(#"Renamed Columns1", "Index", 1, 1),
#"Filtered Rows" = Table.SelectRows(#"Added Index", each [Index] < 13),
#"Changed Type2" = Table.TransformColumnTypes(#"Filtered Rows",{{"YearMonth", type text}}),
#"Invoked Custom Function" = Table.AddColumn(#"Changed Type2", "DataColumn", each Sheet1([YearMonth])),
#"Expanded DataColumn" = Table.ExpandTableColumn(#"Invoked Custom Function", "DataColumn", {"Category", "YearMonth", "Sales"}, {"Category", "YearMonth.1", "Sales"})
in
#"Expanded DataColumn"

I wanted to share the PBIX file with you, but don't have a way to upload it from my corporate network.

Regards

Vicky