You can enroll multiple contacts in Sequences but be careful: the user experience and deliverability can be diminished.
Here are instructions to enroll multiple contacts in Sequences. But be careful, you may not want to enroll multiple contacts in the same Sequence.
One of the nicest features of Hubspot's Sales Sequences tool is that you can personalise the Sequence for each person. Hubspot even gives you tips to improve the personalization of each email before you start the Sequence.
The reason is, Hubspot knows that your email will have a better deliverability if each email is personalized. For example, email filters and people are more likely to mark an email as Spam or send to Junk mail if the email seems impersonal.
So unless your Sequence is already highly personalized to a group of people and all the things they all have in common, you probably do not want to batch enroll contacts in the same Sequence.
Nonetheless, if you see enough commonality to enroll multiple contacts in the same sequence, here is how you could do achieve multiple enrollment.