I want to post a review of a provider who already has other reviews. Is there a way I can post that automatically fills in the existing information about contact and height and weight and all the stuff that is the same? I'll fill in when, and the experience. Thanks for your help.

"Is there a way I can post that automatically fills in the existing information...?"

No.  You must complete all required profile fields when submitting a review.

it does not matter in most cases. This information is part of the provider's profile and the first posted review establishes the profile. So even when a hobbyist enters a change, e.g. change 'smokes' from no to yes, the original information will stay anyway.  This will stay this way forever unless either the provider or a hobbyist 'reports a problem' to the TER review staff and it is accepted.  From my one experience trying to change this once, it is quite a frustrating and time consuming  process and I'm afraid many avoid doing it as a result.

If it didn't require some time and dedication to submit an approvable review; every associate of a less than ethical provider would be submitting one for their friend. The time intensive nature of the process probably helps thwart LE espionage also.