It may happen to you, you have presented yourself well through interview(s) and finally at the end of an interview the HR representative presents you with an offer on the spot. This may be your dream job, or maybe it isn't, however you as a active job seeker, should consider the offer by reviewing it in detail. This is of course with the caveat that there is not a condition where you are given a specific time limit to accept the job offer on the spot. Most of the time this would not be the case, as the company is expressing a commitment that they like you and want you to join their organization, so they will give you time to consider the offer.

Here's what you may want to do:

1. Say thank you (this should be obvious).

2. Express or convey your excitement and interest.

3. Let them know that you would like a few days to consider the offer, and may have more questions as your review the offer including everything else.

4. Ask them how can you contact them either with your decision or with additional questions you may have.

Why should you not simply accept?:

1. As a professional you need to review things such as their benefits package.

2. After you review the offer you may some questions and  you should have a chance to ask them.

3. Additionally you may want to negotiate things like: salary, vacation, remote work etc.

After you are given an offer this may be your one chance to ask for anything you may want additionally.  With all this, ultimately the decision is up to you. However, remember  the worst thing you can do for yourself, if you rush your decision and accept is step into your first day and realize that you should have been more patient, and thorough in your decision, but instead you now you have some regrets.