I have these entries in my OVS after loading a basic setup, and two VMs on the same private network.
They are not expected to be there when not using BGP/MPLS solution. Especially not with specific MPLS labels that are clearly unrelated.
There isn't even any rule pointing to table 20 - this table's use is confusing in the basic usecases (same for ext tunnel table 38)

cookie=0x8000002, duration=6655.984s, table=20, n_packets=0, n_bytes=0, priority=10,mpls,mpls_label=70001 actions=write_actions(pop_mpls:0x0800,group:0)
cookie=0x8000002, duration=5765.057s, table=20, n_packets=0, n_bytes=0, priority=10,mpls,mpls_label=70005 actions=pop_mpls:0x0800,goto_table:25
cookie=0x8000002, duration=5764.454s, table=20, n_packets=0, n_bytes=0, priority=10,mpls,mpls_label=70004 actions=write_actions(pop_mpls:0x0800,group:0)
cookie=0x1030000, duration=6700.027s, table=20, n_packets=0, n_bytes=0, priority=0 actions=goto_table:80