Overflow Eviction_by setting in snappy data

[pancjgithub]

I create a table with EVICTION_BY 'LRUMEMSIZE 2'(please see below sample),it means only 2M data keep in momeroy?
How this parameter works?
If more than 2M data in table,it will overflow to harddisk?(i check the Memory Size of this table in dashboard,it shows more than 2M) .Thanks

Table script:
CREATE
TABLE
app.COL_TABLE_TP10(
PRSN_EVNT_ID BIGINT NOT NULL,
VER BIGINT NOT NULL,
CLIENT_ID BIGINT NOT NULL,
SRC_TYP_ID BIGINT NOT NULL
)
USING COLUMN OPTIONS(
PARTITION_BY 'PRSN_EVNT_ID,CLIENT_ID',
BUCKETS '1',
EVICTION_BY 'LRUMEMSIZE 2',
OVERFLOW 'true'
);