The classify_add_del_table message (CLI also)
deletes whole table chain (it is not documented in the vpe.api file).

That can cause produce inconsistent state if classify tables form a tree:

classify table mask l3 ip4 src
classify table mask l3 ip4 dst next-table 0
classify table mask l2 dst next-table 0
classify table del table 1

Possible fix:
Add parameter to classify_add_del_table to allow single table delete or another binary api message.