Archaeologists found a Davidic-era inscription containing the biblical name “Esh-ba’al”–article’s here. This doesn’t seem to refer to the same man, but it confirms the name’s use in that period. The biblical Esh-ba’al was King Saul’s son (1 Chr 8:33); what’s interesting is that 1 Sam 3-4 call him “Ish-bosheth” instead. Esh-ba’al means “man of Ba’al” or “man of the Lord”; Ish-bosheth means “man of shame” (or, “man of humility).
My take on the names: I think Esh-ba’al was his actual name. But, faithful Hebrews would have had a big problem with a name containing reference to Ba’al. So, they (and the writer of Samuel) substituted “bosheth” (shame) for “ba’al” in the name as a comment on his character (and his father’s). That would be consistent with Jer 11:13, which has a similar wordplay: “altars you have set up to the shameful thing (la-bosheth), altars to burn incense to Baal (la-ba’al).”