Append rows to existing table

Hello, I'm having an issue when appending new rows to existing table

```javascript
const workbook = new ExcelJS.Workbook()
workbook.xlsx.readFile(filename).then(async function () {
let worksheet = workbook.getWorksheet(1)
let table = worksheet.getTable('MyTable')
table.addRow(['One','Two'])
table.commit()
await workbook.xlsx.writeFile(filename)
})
```
I'm getting this error :

```
TypeError: Cannot read property 'length' of undefined
at Table.get height [as height] (C:\Users\SatSuki\Desktop\FootScrap\node_modules\exceljs\lib\doc\table.js:88:32)
at Table.get filterHeight [as filterHeight] (C:\Users\SatSuki\Desktop\FootScrap\node_modules\exceljs\lib\doc\table.js:93:21)
at Table.get tableHeight [as tableHeight] (C:\Users\SatSuki\Desktop\FootScrap\node_modules\exceljs\lib\doc\table.js:98:21)
at Table.cacheState (C:\Users\SatSuki\Desktop\FootScrap\node_modules\exceljs\lib\doc\table.js:272:35)
at Table.addRow (C:\Users\SatSuki\Desktop\FootScrap\node_modules\exceljs\lib\doc\table.js:322:14)
at C:\Users\SatSuki\Desktop\FootScrap\spread.js:62:27
at process._tickCallback (internal/process/next_tick.js:68:7)
```
When appending just after creating the table it works fine.