How to use the "Filter Table" from UiPath.Excel.Activities to filter for values that don't contain a string

It sounds like the case is about
There is a list of Names
Datatable should be filtered on all names, which are in=remove or not-in=keep the list

With Filter DataTable we are not served by OOTB functionalities

With DataTable.Select or LINQ we do have such options

arrBlockNames | String Array = new String(){“MONIKA”, “RIYA”}

Assign Activity:

(From d in YOurDataTableVar
let chk = arrBlockNames.Contains(d("User Name").toString.Trim.ToUpper
Where not chk
Select r =d).CopyToDataTable

Handling empty results:

About LINQ