Could some of the Senate Dems do this and prevent Kavanaugh from taking

[Liberty Belle]

1. No. Senate quroum is 51:

Article I, section 5 of the Constitution requires that a quorum (51 senators) be present for the Senate to conduct business. Often, fewer than 51 senators are present on the floor, but the Senate presumes a quorum unless a roll call vote or quorum call suggests otherwise.

They need 51 votes anyway to confirm Kavanaugh, which they could do without a single Democratic vote if all Republicans voted yes. If they lose a couple then they'd need a Dem or two; I suppose in that case if those Dems didn't want to vote at all, say in a red district, they could just not show up.