@Adamano - As per suggestion, we can used it in the `<apex:form style="white-space: nowrap;">` like below. It works fine.

    <apex:page standardController="contact" extensions="InLineController">
     	<apex:form style="white-space: nowrap;">
           <apex:pageBlock title="My Inline Visualforce page">
            <b>Account Name : </b> <apex:outputField value="{!accRec.name}"/><br/>
            <b>Account Number: </b> <apex:outputField value="{!accRec.accountnumber}"/><br/>
             <b>Annual Revenue : </b><apex:outputField value="{!accRec.annualrevenue}"/>
           </apex:pageBlock>
     	</apex:form>
    </apex:page>

[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/0bzdP.png