This Suda entry reminds us of Diogenes Laertius 7.64 (SVF 2.183), where in the context of a Stoic doxography sumba/mata are said to be included among predicates. Actually they are predicates that can be exemplified by intransitive verbs, such as 'to sail through the rocks'. The issue is also treated in more detail by Porphyry (who recalls Stoic doctrines), quoted by Ammonius (In Aristotelis de interpretatione 44.18-45.7, included in SVF 2.184, where it is said that kathgo/rhma and su/mbama mean the same; 44.24-25). The Byzantine philosopher Stephanus (7th century CE) also discussed this matter in his commentary on Aristotle's De Interpretatione. Stephanus' passage is very helpful, insofar as it explains in what sense an 'event' can be related to a 'predicate': 'what is predicated of something is predicated either of a noun (o)/noma) straightforwardly or of a case (ptw=sis). If it is [predicated] of a noun, it yields either a self-complete assertion or a non self-complete [assertion]; and if [it yields] a self-complete assertion, they call it 'predicate' or 'event', for among them [sc. the Stoics] it is the same and it is clearly the cause. In fact, they say 'predicate' because it is asserted, or it is said and predicated of a subject. But [they say] 'event' (su/mbama) because walking happened (sune/bh) to Socrates. But if it does not yield a self-complete assertion, it is called 'quasi-predicate' or 'quasi-event', such as 'Socrates loves'" (Stephanus, In Int. 11, 9-17, ed. Hayduck; my translation). For other details and bibliography on this issue, see note 1 at rho 131.
[1] See for instance, in brief, Anonymi in Hermogenem, Prolegomena in librum peri stasewn 14.328.22ff Rabe. (This entire Suda entry, however, is not paralleled in anything extant.)