What do 总 and 不时 mean here together?
You need to consider 总会 together:
ABC

be bound to; be inevitable; be sure to happen

总会 + 不时 = be sure to + often = he is bound to frequently.../he is sure to often...
ABC calls 总会, here, a:
Verb Phrase

Dòngcí Cízǔ 动词词组
This includes
(i) descriptive predicates that do not behave as stative verbs, e.g., ǎirán ‘amicable; amiable’, as well as
(ii) phrases and longer chunks containing a verb that are not fixed expressions, e.g., bǎiláibǎiqù ‘sway; waver’, áidào tiānhēi ‘bear up until nightfall’.