Queries :: Adding Data From One Table To Another

I have two tables in access:

TABLE 1:
ID
SINGLE_MULTI

TABLE 2:
ID
NUMBER OF VIEWS
MULTI

The data is a store of all viewers of a video.

Table 1 has all of my unique data within it. People within this table may have watched the video once or several times. People within Table 2 have watched the video several times.

I want to add a flag for "Multi" to Table 1. And, where a person is not a "Multi" create a flag that reads "Single".

I've spent countless hours (probably days) trying to achieve this and have failed miserably. Whatever approach I take I end up creating a new table that just contains the "multi" people.