How to execute a script on all sheets of a table?

Question

Google Apps Script

Help to correct the script so that it does the same but cuts data from all sheets expressed and inserted into another table on sheet "Sheet3"

function copyTabList() {
  var from = SpreadsheetApp.getActiveSheet();
  var fromValues = from
    .getDataRange()
    .offset(1, 0)
    .getValues();
  var fromData = fromValues;

  var tss = SpreadsheetApp.openById('Id');
  var ts = tss.getSheetByName('Sheet3');

  ts.getDataRange()
    .offset(1, 0)
    .clearContent()
    .getSheet()
    .getRange(2, 1, fromData.length, fromData[0].length)
    .setValues(fromData);
}

Answer 1

You can get a list of all sheets and loop through. Copy the data in the same way, but change the line number when inserting (here 2 is replaced by (last line of data on the sheet + 1))

.getRange(2, 1, FromData.length, FromData[0].length)

If you want it to work faster, then you need to form a two-dimensional array of data from all, and then write to the cells at a time. Just add them line by line to a common two-dimensional array when you receive a new portion of data.
Even easier is to use IMPORTRANGE() - everything is pulled from another table there. If you need to write in a column, you can use the array declaration:
={1;2;3}
... will print 1,2,3 in a column. Replace the numbers with formulas with IMPORTRANGE() by the number of sheets and automatically get what you want. The only BUT - the data is read-only