In the invoice, the description is coming in 6 lines instead of 1 or two lines.Even through there are enough space in the line, details after scrolling down after 2 words

I'm here to help you get this sorted out , info. 

We can adjust the width in the Description column to adjust the size to 30. This way, you'll have the 1 or 2 line views. Here's how:

1. Navigate to the Gear icon.
2. Select Custom Form Styles.
3. Locate the desired template and choose the drop-down arrow.
4. Select Content and click Hide Labels and Widths. 
5. Adjust the size to 30 from the Description section. 
6. Then, click Done.

 I've attached a screenshot below for your visual reference.

I'm also adding some related links to help you further with this topic you're asking about:

• Add, customize, or remove logos on sales forms
• Customize invoices, estimates, and sales receipts in QuickBooks Online

Keep your post coming if you need further assistance managing your invoices. I’d be more than happy to help. Have a great day!