with TCsv.Create do
try
  LoadAnsiFile('c:\data.csv');
  ShowMessage(ToString);

  if (LineCount > 1) and (FieldCount[1] > 2) then
    Fields[1, 2] := 'New value';
  ShowMessage(ToString);
finally
  Free;
end;

with TCsv.Create do
try
  LineCount := 10;
  for i := 0 to LineCount - 1 do
  begin
    FieldCount[i] := 3;
    for j := 0 to FieldCount[i] - 1 do
      Fields[i, j] := 'Field ' + IntToStr(i) + ' ' + IntToStr(j);
  end;

  ToUtf8File('c:\new.csv');
finally
  Free;
end;

with TCsvWriter.Create('export.csv') do
try
  Write('Field 1 1');
  Write('Field 1 2');
  Write('Field 1 3');

  NextLine;

  Write('Field 2 1');
  Write('Field 2 2');
  Write('Field 2 3');

  NextLine;

  Write('Field 3 1');
  Write('Field 3 2');
  Write('Field 3 3');
finally
  Free;
end;

• optimized for large data
• selectable field separator
• selectable CR/LF/CRLF output
• selectable enclosing character
• optional white space enclosing
• optimized output, enclosing emitted "as needed"
• WideString or Unicode fields
• UTF8 and Ansi files supported
• UTF8, AnsiString and WideString/UnicodeString data supported
• lines with variable number of fields supported
• insertion and deletion of lines and fields supported
• supports Windows, macOS, iOS and Android
• available for Delphi/C++ Builder 6 - 10.4 and Lazarus 2.0.8
• source code included in registered version
• royalty free distribution in applications