7250K for E2E, 250K for WebNLG, and 500K for DART

versus 345M GPT-2 parameters.

8The S,U,A columns in WebNLG represents SEEN, UN-
SEEN, and ALL respectively; SEEN categories appear at
training time; UNSEEN categories only appears at test time;
and ALL is the combination of the two.

(1) XSUM contains 4x more examples than the
three table-to-text datasets on average; (2) the input
articles are 17x longer than the linearized table in-
put of table-to-text datasets on average; (3) summa-
rization is more complex than table-to-text because
it requires selecting key contents from an article.
Prefix-Tuning