var htmlTemplateFile = ".//03.Tables.htm";

Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);

var html = await File.OpenText(htmlTemplateFile).ReadToEndAsync();

var pdf = HtmlRendererCore.PdfSharp.PdfGenerator.GeneratePdf(html, PdfSharp.PageSize.A4);

var generatedPdfFile = ".//03Tables.pdf";

pdf.Save(generatedPdfFile);