Select Tables based on Name

try if this scheme is what you want

let
    Source = Excel.Workbook(File.Contents("C:\Users\37332115\OneDrive - TIM\MyD2020\BI\tabelle.xlsx"), null, true),
    #"Filtered Rows" = Table.SelectRows(Source, each Text.Contains([Name], "opex")),
    #"Removed Other Columns" = Table.SelectColumns(#"Filtered Rows",{"Data"})
in
    #"Removed Other Columns"

Load all the tables and filter by content of name.

then combine the tables filtered in

let
    Source = Table.Combine(foglio1[Data])
in
    Source

Hello Andyb431 

here the approach you can use.

let
    Source = Excel.Workbook(File.Contents("YourExcelFile"), null, true),
    SelectNameSheet = Table.SelectRows(Source, each Text.Contains(Text.Upper(_[Name]), "OPEX")),
    CombineTable = Table.Combine(SelectNameSheet[Data])
in
    CombineTable

The only thing that you have to pay attention is your format of the table in Excel. Its a blank sheet with the data in or it is a table? The problem of combining only the sheet-data is that you will get a table with Column1, Column2 as header, and thats not nice. Then you would need to transform the tables before and then combine. Here a solution to this

let
    Source = Excel.Workbook(File.Contents("YourExcelFile"), null, true),
    SelectNameSheet = Table.SelectRows(Source, each Text.Contains(Text.Upper(_[Name]), "OPEX")),
    TransformTables = Table.TransformColumns
    (
        SelectNameSheet,
        {
            {
                "Data", 
                each Table.PromoteHeaders(_)
            }
        }
    ),
    CombineTable = Table.Combine(TransformTables[Data])
in
    CombineTable

Copy paste this code to the advanced editor in a new blank query to see how the solution works. If this solution fits your need, copy and past a part of it and implement it in your query, or I could create a custom function what makes it easier to apply if you are not used that much to power query.

If this post helps or solves your problem, please mark it as solution (to help other users find useful content and to acknowledge the work of users that helped you)
Kudoes are nice too

Have fun

Jimmy