Ниже код работал для меня:
import * as FileSaver from 'file-saver';
import * as XLSX from 'xlsx';
exportexcel(): void {
let element = document.getElementById('excel-table');
const worksheet: XLSX.WorkSheet = XLSX.utils.table_to_sheet(element);
const workbook: XLSX.WorkBook = { Sheets: { 'data': worksheet }, SheetNames: ['data'] };
const excelBuffer: any = XLSX.write(workbook, { bookType: 'xlsx', type: 'array' });
const blob: Blob = new Blob([excelBuffer], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=UTF-8' });
FileSaver.saveAs(blob, 'Data.xlsx'));
}