How To Set Format Value in tablegrid

You should use type CURRENCY for field, where you can activate thousand separator:

You should use calculate field, an example:

strftime('%d.%m.%Y', datefield, '+4 years')

My Visual Database uses user's regional format, but if you need, you can change format in the tablegrid using script, an example:

procedure Form1_GridEmployees_OnChange (Sender: string);
var
   i,c: integer;
   sTime: string;
begin
     Form1.GridEmployees.BeginUpdate;

     c := Form1.GridEmployees.RowCount - 1;
     for i := 0 to c do
     begin
         sTime := Form1.GridEmployees.Cells[4,i];

         if sTime<>'' then
             Form1.GridEmployees.Cells[4,i] := FormatDateTime( 'hh:mm ampm', StrToTime(sTime) );
     end;

     Form1.GridEmployees.EndUpdate;
end;

Hello JRGA,
It sounds as if, in the edit field on the form where you are entering your value, you have ticked the 'currency' object property.  If so, then make sure that you also set the 'accuracy' object property to '2'.  If you set the one without setting the other, the value will only show whole numbers.
Alternatively, leave both of these two object properties as their defaults ('unticked' and 0') and allow the program to use the original definitions that you specified when defining your table.
Hope this is clear and helps,
Derek.