Viewer:  https://mozilla.github.io/pdf.js/web/viewer.html
Chrome on Windows 10
When the attached PDF file is viewed, some of the fonts display as garbled text. 
[Arial, Courier, Times New Roman]
The file views correctly in Adobe Reader.
[fff.pdf](https://github.com/mozilla/pdf.js/files/4652174/fff.pdf)

const tables = Object.create(null);
      tables["OS/2"] = null;
      tables.cmap = null;
      tables.head = null;
      tables.hhea = null;
      tables.hmtx = null;
      tables.maxp = null;
      tables.name = null;
      tables.post = null;
      for (let i = 0; i < numTables; i++) {
        const table = readTableEntry(file);
        if (!VALID_TABLES.includes(table.tag)) {
          continue; 
        }
        if (table.length === 0) {
          continue; 
        }
        tables[table.tag] = table;
      }
      return tables;
    }
    function readTableEntry(file) {