I've got a solution on how you can fix this, app-nomad-us.

We can adjust the widths of each columns in your invoice template by following these steps:

1. Go to the Gear > Customer Form Styles.
2. Click the Edit link of the default invoice template.
3. Select the Content tab and click on the activity section.
4. Under Columns, tick the Edit Labels and Widths link.
5. Adjust the columns. You can also checkbox the Collapse activity rows.
6. Hit Done.

Please see this sample screenshot for a visual reference:

Once done, open your invoice then try to preview and print. 

For more customization on your sales template, feel free to read this article: Customize invoices, estimates, and sales receipts in QuickBooks Online.

Please let me know how it goes. I'll be around to help you out again. Take care!