Hi Stephane, try this for Selected Table Only

//Start Simple Window
var w = new Window (‘dialog’);
w.text = ‘Change Table Columns Width’;
w.preferredSize.width = 280;
w.group = w.add (‘group’);
var RadioPanel1 = w.add(‘panel’, undefined, undefined, {name: ‘myGroupS’});
var StaticaStart = RadioPanel1.add(‘statictext’, undefined,’Enter Table Columns Width’);
var myString = RadioPanel1.add (‘edittext’, undefined, ‘100, 100, 150, 150’, {readonly: false}); //read only prevent user Entering Nums
myString.alignment = ‘center’;
myString.characters = 20;
w.buttons = w.add (‘group {alignment: “center”}’);
w.ok = w.buttons.add (‘button {text: “OK”, enabled: true}’);
w.buttons.add (‘button {text: “Cancel”}’);
//After Interface
//Showing the Dialog
var a = w.show()
//if User Hit Cancel
if(a == 2){
exit(0);
}

//Run with UNDO Enabled
app.doScript(doColumnWidth, ScriptLanguage.JAVASCRIPT, undefined, UndoModes.ENTIRE_SCRIPT, “Change Selected Table Column Width”);

function doColumnWidth(){
//Convert String to Array
var WidthVar = (myString.text);
var TargetWidthArray = eval(‘[‘+WidthVar+’]’);
//Script
var mySelection = app.selection[0];
var myWidths = TargetWidthArray;
for(var i=0; i < mySelection.tables.length; i++){
for(var j=0; j < myWidths.length; j++){
mySelection.tables[i].columns[j].width = myWidths[j];
}
}
alert(“Table width updated successfully…”);
}