Filter DataTable-The output row count is the same as input

Have a look at this LINQ

Assign Activity
dtFiltered =

(From d in YourDataTable.AsEnumerable
Let v = d(3).toString.Trim
Let chk = {"100","200"}.Any(Function (x) v.StartsWith(x))
Where not chk
Select r = d).CopyToDataTable

Handling empty result:
:ambulance: :sos: [FirstAid] Handling of The source contains no DataRows exception - News / Tutorials - UiPath Community Forum

Debugging / Inspection / Tracing / Prototyping
Understanding the 6 Debugging Panels of UiPath in the easiest way possible! - News / Tutorials - UiPath Community Forum

EDITED: with the hint of @supermanPunch
changed 4 to 3